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Camper Van Electrical System (A Beginner’s Install Guide)

For many, installing the camper van electrical system is often the most challenging part of converting a camper van. With so many different components, wires, and calculations, it’s easy to feel overwhelmed!

For almost a decade, we’ve done extensive research on van electrics, built several systems of our own, and acquired valuable real-world experience to know what works and what doesn’t. This post will share everything we’ve learned throughout our electrical journey and explain what you need to know to build your van’s electric system.

Below are some of the topics we will cover.

  • Auxiliary batteries: The different types and how many you’ll need.
  • 12V system: Powering LED lights, a vent fan, and more directly from the batteries.
  • 120V system: How to run household appliances in a van from an inverter.
  • Battery charging: Charging the batteries from solar panels and the van’s alternator.
Camper van parked in the desert displaying various electrical components like solar panels, lights, and water kettle.

Along the way, we’ll share helpful wiring diagrams and recommended products to help you build your electrical system quickly, efficiently, and safely.

If you’re ready for the challenge, we’re here to help. So let’s go!

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Intro: Essential Parts of an Electrical System

A complete camper van electrical system comprises three general sections in its most basic form.

  1. Power Storage. Batteries store the power (Watts) required to run electrical devices.
  2. Power Out. These are the loads that require power from the batteries to operate.
  3. Power In. These are the charge sources that supply power to the batteries.
Charge sources, like solar panels and shore power, putting power into a battery. Loads taking power from the same battery.
It’s all about managing power into and out of the battery.

Understanding this power flow into and out of the battery is essential to installing a functional and practical electrical system in your camper. Below, we cover each of these three parts in more detail.

Power Storage (‘Batteries’)

Batteries are the ‘de facto’ power storage solution for camper vans. They stockpile the energy the charge sources provide and distribute the power to the loads when needed.

Batteries come in different chemistries (e.g., lithium and lead-acid), power capacities, and voltages. You can also combine multiple batteries to increase the energy you can store in your van.

Learn more: Skip to Chapter 1 for more information about camper van batteries. We discuss which types of batteries are best for van life, how many batteries you’ll need, and how to wire multiple batteries together.

Power Out (‘Electrical Loads’)

When utilized, electrical loads pull power from the batteries. The more power that flows out of the battery, the faster the battery is discharged. Examples of common loads in van conversions include:

  • LED lights
  • Water pumps
  • Smartphone & laptop charging
  • Fridges
  • Ventilation fans
  • Diesel heaters
  • Water kettle & other kitchen appliances

Good to know: Most electrical loads in a camper van won’t demand much battery power. The the big picture, LED lights and water pumps, for example, have minimal effect on total power consumption. However, other loads, such as electric water kettles and fridges, can discharge a battery much faster due to their higher power consumption. It all comes down to how many watts a device requires and for how long it is operating.

Power In (‘Charge Sources’)

You must put power into the battery to charge it. Although there is a wide variety of ways to charge a battery, the four most popular charge sources are:

  1. Solar panels. These panels convert sunlight into usable power. Solar is the #1 way we charge our batteries.
  2. Vehicle alternator. Connecting to the alternator allows the battery to charge while the engine runs.
  3. Shore power. This involves plugging the battery into the electric grid via an external socket, usually found at a campsite or home.
  4. Generator. Portable generators use either gasoline or propane (LPG) to create power, which is then fed to the batteries.

Our Opinion: We believe in utilizing a MINIMUM of two charge sources. Most van conversions go with solar panel and alternator charging solutions. This ensures your battery receives sufficient power daily to power the loads.

Skip to a Specific Section

The rest of this post is divided into chapters based on power storage, power out, and power in. We recommend reading each chapter in sequence, but you can click the link below to skip to a specific chapter.

Chapter 1:

Batteries

The batteries are the “heart” of a camper van’s electrical system and should be the first part to plan for. Just like how an actual heart receives and pumps blood to all the vital organs in the body, a battery receives, stores, and distributes power to all the various electrical loads in a camper van.

Li Time lithium battery and Redodo Mini lithium battery sitting side-by-side
LiTime TM and Redodo Mini batteries

It is worth your time to learn about camper van leisure batteries. Buying the wrong type or not having enough batteries jeopardizes the electrical system’s ability to provide sufficient power to your loads daily.

This chapter covers three essential battery topics.

  1. Different battery types (AGM vs Lithium)
  2. Calculating your ideal battery size
  3. How to wire multiple batteries together

1.1 – Basic Battery Terminology

Before delving deeper into van battery specifics, it’s essential to learn the basic terminology so that you’ll know what we’re talking about later on (and throughout this electrical guide).

Power Capacity (Amp-hour & Watt-hour)

This is the amount of energy that can be stored in a battery. The most common unit of measurement for a battery’s storage capacity is Amp-hours (Ah). For example, most batteries used in camper vans are rated for 100Ah. Below is an image of a popular battery, and you can readily see its 100Ah power capacity rating.

When comparing batteries that operate at the same voltage (for example, 12V), look to the battery’s Ah rating to determine its power capacity. If the voltage is the same, a 100Ah battery will have half the energy capacity of a 200Ah battery.

“Watt-hours” (Wh) is a more correct method of identifying total power capacity, but it is less frequently used in real life. For this reason, we will not use Watt-hours much in this electrical post. To identify a battery’s watt-hour capacity, multiply the battery’s amp-hours (Ah) by its voltage. For example, 100Ah x 12V is 1,200Wh.

Operating Voltage

Volts (V) are the unit of electromotive force. In simple terms, voltage is the pressure (or speed) at which energy is pushed through a circuit.

The vast majority of batteries used in camper vans operate at 12 volts. However, some vans choose to use 24V and 48V batteries, and each type has its pros and cons.

Our opinion: If it is your first time building a camper van electrical system, we recommend going with a 12V battery system. But if you want to do more research, read our 12V vs. 24V battery system comparison.

Depth of Discharge

This is how deep a battery is discharged from 100%. For example, if you say that your battery “regularly experiences a depth of discharge (DoD) of 70%”, it would mean that the battery regularly goes down to 30% charge before being recharged back to 100%.

Charge Cycles

One charge cycle is the process of discharging and charging a battery once. “Charge cycles”, in general, refer to a battery’s expected lifespan. Different battery chemistries have different charge cycle lifespans.

A battery’s charge cycle lifespan also depends on how much DoD the battery regularly experiences. The greater the DoD, the fewer charge cycles the battery will have before needing to be replaced. We also provide several tips to help prolong your battery’s lifespan.

1.2 – Types of Batteries (Chemistries)

Four different battery chemistry types can be used in a camper van. They are:

  • Flooded Lead-Acid (FLA)
  • Gel Cell
  • Absorbent Glass Mat (AGM)
  • Lithium-Ion (LiFePO4)

We DO NOT recommend flooded lead-acid and gel cell batteries. This is because FLA batteries require regular maintenance, and Gel Cell batteries require slower charge and discharge rates, which may not be compatible with van life. Additionally, both FLA and Gel battery technologies have shorter lifespans compared to AGM and lithium batteries. (Source)

Our opinion: Only AGM and lithium (LiFePO4) batteries offer realistic solutions for camper vans. And for the vast majority of van conversions, you should be looking to buy lithium. Lithium battery prices have declined tremendously over the past decade and the conventional wisdom that “lithium is expensive” is no longer valid.

Lithium vs. AGM Batteries

Although we believe lithium batteries are the clear winner, we compare them to AGM batteries below.

Comparison Table

Though AGM and lithium batteries differ in many categories, we select and highlight the ones that matter.

AGM1Lithium2
Power capacity100Ah100Ah
Weight64 lbs (29 kg)23 lbs (11 kg)
Sensitive to sub-freezing? 3NoYes
# of charge cycles 45004000
Cost (upfront) 5$190$300
Cost (per charge cycle)$0.38$0.075
Better deal?Yes!

Table Footnotes:
1. Renogy 200Ah x 12V AGM battery
2. LiTime 100Ah x 12V lithium battery
3. Lithiums cannot be charged if below freezing.
4. Lithium @ 100% DoD & AGM @ 50% DoD
5. Prices in March 2024

AGM vs. Lithium Essential Takeaways

Based on the table above, we break down the three most consequential issues when comparing AGM and lithium batteries.

  • Lifespan: Under similar discharge situations, lithium batteries will have a lifespan of 6-8 times longer than AGMs. From our experience, if you can get more than 1.5 years of service life from an AGM battery, that’s pretty good.
  • Cost: AGM batteries tend to have a lower upfront cost ($ per Ah) than lithium. However, lithium batteries are significantly cheaper ($ per charge cycle) when considering the lifespan of both batteries. AGM batteries are only a good deal if you are on a tight budget, and saving every dollar matters.
  • Temperature sensitivity: Attempting to charge a lithium battery while in sub-freezing temperatures can break the battery. Consequently, AGM batteries can excel if you plan to travel long-term in freezing environments. However, modern lithium batteries have built-in monitoring and heating systems, making this issue irrelevant.

Battery Recommendations

Which batteries do we like? Our battery recommendations fall into three categories.

  1. Premium lithium. This type of battery is for those where money is no concern and premium quality, customer service, and warranty are prioritized. Batteries are usually made in the USA or Europe.
  2. Budget lithium. This battery is for those who still want to invest in a quality lithium battery, but getting the most value for every dollar spent is essential. Batteries are usually made in China.
  3. Budget AGM. This is for those who have extremely tight budgets, and saving every dollar is mission-critical.

Our opinion: Get a “budget lithium” battery. With an extremely low “cost per charge cycle”, budget lithiums represent the best value on the market today and are 1/3 the price of premmium lithium brands. But not all budget lithium brands are equal. Some are REALLY cheap and use poor-quality components. “Li Time” batteries have been frequently taken apart and reviewed to have genuinely high-quality parts and assembly. We have also personally reviewed the Li Time “TM” lithium battery and came away impressed.

Premium Lithium
Budget Lithium
Budget AGM

You get what you pay for. Batteries made in the USA with premium components.

Top recommendation. Get the power of lithium at a great price. Will Prouse on YT loves Li Time batteries, and so do we.

Weize AGM batteries are often the lowest price on Amazon. We recommend for extreme budget builds.

Premium Lithium

You get what you pay for. Batteries made in the USA with premium components.

Budget Lithium

Top recommendation. Get the power of lithium at a great price. Will Prouse on YT loves Li Time batteries, and so do we.

Budget AGM

Weize AGM batteries are often the lowest price on Amazon. We recommend for extreme budget builds.

1.3 – Battery Bank Sizing

Most individual batteries have a power capacity of 100Ah. But this doesn’t mean you are limited to buying just one battery for your camper van’s electrical system. You can combine multiple batteries to increase the total power capacity.

"Battery Bank"
A battery bank is made up of two or more batteries connected together.

Most modern camper vans require so much power that a single 100Ah battery won’t cut it. With just one battery, your van is likely to experience power outages—at least some of the time. That’s why it’s essential to do a power audit of your van’s electrical system to know how much power your system requires in each 24-hour period. The more energy consumed, the more batteries you’ll need to support the electrical system.

One battery powering four devices and two batteries powering 13 devices, including laptops, fridge, fan, and more.
More batteries = more power capacity

Since different camper vans have different sets of devices, each van will require battery banks of different sizes. Some electrical systems may only need a 100Ah battery, but larger systems may require a 200Ah, 300Ah, or even 400Ah battery bank.

Free Battery Size Calculator

Download and use our free battery calculator tool below to determine your ideal battery size.

Calculator summary: Follow these steps to calculate the battery power needed to sustain your camper’s electrical system.

  • List out all electrical devices. This includes lights, fans, phones, etc.
  • Calculate daily power usage (Wh) for each device. This involves multiplying the wattage rating of each device by the number of hours that the device is in operation.
  • Sum together all the Watt-hours for each device.
  • Divide sum by 12. The result is your van’s minimum Ah battery bank size (12V system).

For a detailed step-by-step tutorial, read: How to calculate your ideal battery size.

1.4 – Connecting Multiple Batteries

Connecting multiple batteries increases total power capacity. This section covers everything you’ll need to know about how to do this, such as:

  • Parallel vs. series wiring
  • Recommended cable size (AWG)
  • How to attach lugs (ring connectors) onto wire ends

Parallel vs. Series Wiring

Batteries can be wired together in parallel or in series. Both parallel and series wiring will increase teh battery bank’s total power capacity, but depending on which wiring method you choose, you can manipulate the total Amp-hours (Ah) and the battery bank’s voltage.

Parallel Wiring
Three Battle Born lithium batteries connected in parallel
Three batteries connected in parallel

To connect multiple batteries in parallel, connect all the positive terminals together and all the negative terminals together. The total current (Ah) increases, but the overall voltage (V) stays the same.

  • Amps (Ah): Adds Up
  • Voltage (V): Stays the same

Our Opinion: For most van conversions, wiring multiple batteries in parallel is the way to go. You’ll want to build a 12V system by using 12V batteries. Consequently, you’ll will need to increase the Amp-hours (Ah) while keeping the voltage constant.

Series Connections
Three Battle Born lithium batteries connected in series
Three batteries connected in series

To connect multiple batteries in series, connect the first battery’s negative terminal to the second battery’s positive terminal. Then, connect the negative terminal of the second battery to the positive terminal of the third battery. And so on. The effect is that the voltage of the battery bank increases, but the overall amount of current does not increase.

  • Amps (Ah): Stays the same
  • Voltage (V): Adds Up

Wiring batteries in series, which increases the voltage, is useful if you want to build a 24V or 48V battery bank. While there are advantages to building an electrical system that operates at a higher voltages, we think that the cons outweigh the pros, especially for first-time camper van converters.

Recommended Battery Cable Size (AWG)

Three auxiliary batteries wired together with unknown wire size.
Which wire size to use?

The leisure battery’s cable size depends on how many amps (A) will flow through the wires. The greater the amps, the thicker the wire gauge (AWG) you will need.

AWG = "American Wire Gauge"
This is the standardized wire thickness measurement system used in the United States. The smaller the number, the thicker the wire. For example, 14 AWG wire is thinner than 4 AWG wire.Additionally, the more zeros, the thicker the wire. For example, 0000 (4/0) AWG wire is thicker than 00 (2/0) AWG wire, which is thicker than 0 (1/0) AWG wire. (View AWG size table)

The ‘technically correct’ method: To calculate the total amps flowing through the battery cables, you must sum the wattage (W) of every electrical device in your camper van. Then, divide this total wattage by 12 to get the total amps. Take your total amps and refer to this wire amperage chart to determine the ideal battery cable size.

The better method: For a faster, simpler, and safer approach, follow our wire size recommendation below, which is based on the wattage rating of your chosen inverter.

  • No inverter: 2 AWG
  • 1000W inverter: 1/0 AWG wire
  • 2000W inverter: 2/0 AWG wire
  • 3000W inverter: 4/0 AWG wire

For example, if you intend to install a 2000W inverter, you should connect your batteries together with 2/0 AWG wire. Scroll down to our inverter sizing calculator if you haven’t already decided what inverter wattage you need.

The brand we recommend most for battery cables is Windynation. These wires consist of 100% pure copper, stranded conductors encased in thick EPDM rubber insulation for high-temperature resistance. Windynation is based in the USA, and each cable is handcrafted at its workshop in California.

No Inverter
1000W Inverter
2000 Inverter
3000 Inverter

35mm²

55mm²

70mm²

120mm²

No Inverter
1000W Inverter
2000 Inverter
3000 Inverter
Battery Cable Video Review

We review high-quality EWCS 2/0 AWG wires in the video below. These wires are virtually identical to the Windynation wires we recommend above but are more expensive. If we built another camper van, we would go with Windynation instead.

EWCS 2/0 AWG Wire Review - Welding & Battery Cable

Attaching Lugs (Ring Connectors) Onto Wire Ends

To connect the copper wire to a battery, you must crimp a lug terminal (aka ring connector) onto the end of the wire. The lug then connects to the corresponding terminal post on the battery.

A red and a black wire attaching to the positive and negative battery terminal posts via lug terminals.

Below is an image of a lug terminal after it’s been attached to the battery cable.

Lug terminal crimped onto 2/0 AWG battery cable
2/0 wire with lug crimped on
How To Size a Lug

Every lug is designed to fit precisely one wire size and one terminal post size. So, before you purchase your lug terminals, you need to know what cable size (AWG) you are using and the size of the terminal post on your battery.

Lug terminal graphic indicating location of ring size and neck wire size.

Hint: Most batteries, like the LiTime batteries we recommended earlier, use 5/16″ (M8) terminal posts. (Battle Born batteries are the only batteries that we know of that use 3/8″ (M10) posts.

We recommend buying lug terminals from Wirefy, an American-owned company. These lugs are constructed using thick, annealed copper for excellent power transmission. Heat shrink tubing is also included.

Wirefy | Lugs (2/0 x 5/16")

This specific copper lug size (M8) crimps onto 2/0 AWG wire and connects to most battery terminals and inverters. These are pure copper lugs for efficient power transfer.

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Tools You’ll Need

To crimp a lug onto the wire end, you’ll need the following four tools. Watch our video to learn how these tools are used.

 
 
 
 

Cuts through battery cables up to 2/0 AWG.

Cuts away the wire's EPDM rubber jacket insulation.

Crimps the lug terminal on to the wire end.

Activates the heat shrink tubing over the lug and wire.

Cuts through battery cables up to 2/0 AWG.

Cuts away the wire's EPDM rubber jacket insulation.

Crimps the lug terminal on to the wire end.

Activates the heat shrink tubing over the lug and wire.

Watch the video below to learn how these four tools work together to attach a lug to a battery cable.

How To Crimp Lug Terminals Onto Electrical Wire

For a step-by-step tutorial, read: How to crimp lugs onto electrical wire.

Chapter 2:

The 12V DC System

For most van conversions, the 12V DC system is the most important ‘power out’ section of a camper van electrical system. This is because most of the van’s electrical devices will be powered directly from the batteries (12V DC power) without needing a voltage converter (i.e., an inverter).

What kind of devices run on 12V power? Lots of things! 12V electricity can power a wide range of devices, including LED lights, vent fans, smartphones, and more.

12V DC power from a battery can power lights, usb sockets, fridges, diesel heaters, air compressors, smartphones, and fans.

This chapter covers the following 12V topics:

  • Why you should utilize 12V power.
  • Step-by-step installation tutorial.
  • List of popular 12V devices.

2.1 – Why You Should Utilize 12V Power

Since your batteries already operate on 12V power, it is the most power-efficient to identify electrical devices that also operate on 12V and can be run directly from the batteries.

Power inefficiency: If you were to run 120V devices from the battery via an inverter, you would lose 10-15% efficiency because the inverter requires power to convert the voltage. In a camper van, because power is not unlimited (unlike traditional homes that are connected to the power grid), being efficient with your power usage is essential.

A 12V battery powering 12V lights and an inverter powering 120V lights. Power is being utilized more efficiently with the 12V lights.
Power is lost when sent through an inverter

Key takeaway: Prioritize 12V products instead of their 120V counterparts. Get a 12V fridge instead of a 120V fridge. Buy a 12V fan instead of a 120V model, and so on.

2.2 – 12V System Installation Guide

Building a functional 12V electrical system that directs power from the batteries to each of your 12V devices isn’t difficult. Yes, many components and different wire sizes are involved, but we’re confident that if you follow our install guide, you’ll have a 12V system that is functional, sized appropriately, and safe.

Complete camper van 12V wiring diagram connecting leisure batteries to 12V devices
Complete 12V wiring diagram for camper vans

To help you better understand the above 12V wiring diagram, we divided this installation tutorial into three parts.

  • Step 1: Batteries to bus bars
  • Step 2: Bus bars to 12V panel
  • Step 3: 12V panel to individual devices

Do you just need a list of the components? Our 12V system parts list post has an itemized breakdown with video product reviews.

Step 1: Connect the Batteries to the Bus Bars

The first step is to connect the batteries to the bus bars. Below is the wiring diagram showing what you’ll need to connect the batteries to the bus bars. We’ll also help you select the correct wire size, components, and lug terminals.

Wiring diagram for camper vans connecting leisure batteries to bus bars. Includes fuses, battery switch, and battery monitor.
Wiring 12V batteries to bus bars
What are 'bus bars'?
Bus bars are power distribution & collection centers. Once bus bars are connected to the batteries, you connect all downstream electrical components (e.g., inverters, charge controllers, and fuse panels) to these bus bars instead of directly to the batteries. This keeps your wiring system clean and simple.
Recommended Wire Size

When choosing the ideal wire size to connect the batteries to the bus bars, we recommend sizing the wire based on the wattage rating of your inverter. This is the same strategy we recommended in Chapter 1.

Locate the wattage rating of your inverter below to identify the appropriate wire size for your system.

  • No inverter: 2 AWG
  • 1000W inverter: 1/0 AWG wire
  • 2000W inverter: 2/0 AWG wire
  • 3000W inverter: 4/0 AWG wire
No Inverter
1000W Inverter
2000 Inverter
3000 Inverter

35mm²

55mm²

70mm²

120mm²

No Inverter
1000W Inverter
2000 Inverter
3000 Inverter

The above wiring diagram uses 2/0 AWG wires because we will be connecting a 2000W inverter to the bus bars in Chapter 3.

Avoid cheap wires. Our wire sizing recommendations assume you will use 100% pure copper wires. Copper-clad aluminum (CCA) wires are cheaper but can transmit fewer amps at the same thickness as pure copper wires.

Recommended Components

Below are the four components we recommend for connecting the batteries to the bus bars. Our 12V parts list provides more detailed information for each product, including video reviews.

 
 
 
 

Protects wire from overheating.

Disconnects battery from electrical system.

Displays battery state-of-charge percentage.

Power distribution & collection

Protects wire from overheating.

Disconnects battery from electrical system.

Displays battery state-of-charge percentage.

Power distribution & collection

Additional reading: How to install a battery monitor in a van

ANL Fuse Sizing

The fuse amp rating you’ll need depends on the wire size you selected earlier. The thicker the wire, the larger the fuse rating required. Use the list below to identify which fuse size you need.

Recommended Lug Sizes

You will need lug terminals to connect your wire to the recommended components. Some components (e.g., ANL fuse) require lugs with a 5/16″ ring diameter. Other components (e.g., battery switch, battery monitor, & bus bar) require lugs with a 3/8″ ring diameter.

Review the color-coded lug size chart below and refer to the previous “battery to bus bar” wiring diagram to see where each lug is used.

Two lug terminal sizes. One, in dark orange has a 3/8" ring diameter. The other, in peach color, has a 5/16" ring diameter.

Note: You must finalize your wire size BEFORE buying the lugs. If you use 2/0 AWG wires, the lugs below will work.

Watch our Wirefy Lug review below to learn more about lugs, their dimensions, and how to crimp them onto electrical wire.

Product Review - Wirefy 2/0 AWG Copper Lug Ring Terminals

Step 2: Connect the Bus Bars to the 12V Panel

The next step is to connect the bus bars to the 12V fuse panel. This panel distributes the 12V power from the batteries to each 12V device, such as the lights, fan, fridge, and more.

This diagram shows how to connect the bus bars to the 12V fuse panel. Below the diagram, we’ll help you select the correct wire size and components.

Wiring diagram connecting bus bars to 12V fuse panel
Bus bars to 12V fuse panel
Recommended Wire Size

We recommend 4 AWG wires to connect the bus bars to the fuse panel. Windynation rates its 4-gauge wire at 150A, but the Blue Sea Systems fuse panel we recommend is rated for 100A. This means the wire will not limit the fuse panel, which is what we want.

Blue Sea Systems also recommends using 4 or 6 AWG wire. We use the larger wire for maximum safety.

12V fuse panel specifications from Blue Sea Systems indicating that 4 or 6 AWG wire must be used to connect to the panel.

Like the battery cables, we recommend Windynation-branded 4 AWG wires. With an extremely high strand count of 100% pure copper conductors, these wires provide maximum flexibility, ideal for wiring in tight spaces.

Windynation | 4 AWG Wire

100% stranded copper wire. Rated for 150 Amps of continuous current and is ideal for connecting the bus bars to the 12V panel. Resists UV, water, oil, and salt corrosion.

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Watch our Windynation 4 AWG wire review below to see why we recommend these wires for van life.

Windynation 4 AWG Wire Product Review
Recommended Components

To complete this wiring section, you will need a circuit breaker and a 12V fuse panel. We recommend spending a few more dollars on a good-quality fuse panel from Blue Sea Systems. A fuse panel constantly receives and distributes 12V power, and you don’t want the plastic from a cheaper model to melt and shut down your van’s electrical system (we’ve seen it happen).

 
 

Protects 4 AWG wire from overheating. Watch YouTube review.

Distributes 12V power from the batteries to each end device. Watch YouTube review.

Protects 4 AWG wire from overheating. Watch YouTube review.

Distributes 12V power from the batteries to each end device. Watch YouTube review.

Why a 120A circuit breaker? Blue Sea Systems recommends a maximum 125A fuse/breaker in their wiring schematic. So, a 120A breaker will be effective.

Blue Sea Systems fuse panel wiring schematic indicating a maximum fuse rating of 125 amps.
Blue Sea Systems fuse panel wiring schematic
Recommended Lug Sizes

To complete this section, you will need lug terminals with two different ring diameters (3/8″ and 1/4″). Refer to the lug size color chart below and locate the corresponding lugs in the earlier wiring diagram.

Two lugs with 4 AWG neck sizes. The dark green lug has a 3/8" ring diameter and the light green lug as a 1/4" ring diameter.

To save money, we recommend getting a lug terminal variety set, which covers 2 to 8 AWG wires. This set includes the 1/4″ and 3/8″ lugs you’ll need for this section and other lug sizes for different parts of the electrical system (e.g., solar, inverter, and alternator charging). Without a lug set, you would end up buying each lug size separately, which is more expensive and wasteful.

Sanuke | Lug Terminal Set

Save money with this convenient lug terminal set. It covers 12 different lug sizes from 2-8 AWG wires and M6-M10 ring diameters. Heat shrink is also provided.

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Watch our Sanuke lug set review below. With so many different-sized lugs, this kit will help you save money and reduce waste when building your electrical system.

Product Review - Sanuke Copper Lug Ring Terminal Set (With Heat Shrink)

Step 3: Connect 12V Panel to Each Device

In this final step, connect the fuse panel to your 12V devices. The wires and components needed to complete this section are shown in the diagram below.

Wiring diagram connecting the 12V fuse panel to individual 12V devices
12V fuse panel to 12V devices
Recommended Wire Size

14 AWG wire is the ideal size for connecting all 12V devices to the fuse panel. These wires can handle up to 180W of power (15A) at 12V, which is more than enough for each device.

We recommend getting 14/2 AWG “twin wire”, which means two 14 AWG wires (red and black) are encased in a white outer jacket. This jacket provides an additional layer of protection against driving vibrations, sliced wires, and short circuits.

GS Power | 14 AWG Wire

Get this 14AWG wire for all your 12V device connections. We like the tough outer jacket that protects the inner wires from the constant vibrations when driving. These tinned copper wires are 'marine grade' for superior resistance against corrosion.

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We recommend 14/2 AWG twin wire from GS Power. Watch our product review below to learn more.

14 AWG Wire Product Review - GS Power

Avoid voltage drops for longer circuits. If the circuit between the fuse panel and 12V device will be longer than 20′, consider upgrading to 12/2 AWG wire to combat voltage drop across long wiring distances.

Recommended Components

You’ll need the following components to connect the fuse panel to each of your 12V devices. Refer to the earlier wiring diagram to see where these components are placed.

 
 
 

Crimps onto 14-gauge wire and connects to the 12V fuse panel.

Extends the red & black wires from each 12V device to the fuse panel.

Insert these blade fuses into the appropriate slots in the 12V fuse panel to complete each circuit.

Crimps onto 14-gauge wire and connects to the 12V fuse panel.

Extends the red & black wires from each 12V device to the fuse panel.

Insert these blade fuses into the appropriate slots in the 12V fuse panel to complete each circuit.

Blade fuse sizing: Blade fuses come in different amp ratings (color-coded). To calculate the correct fuse size for each 12V device, find the device’s peak current draw and round up to the next fuse size. For example, the Maxxair vent’s fan uses a maximum of 5A of power. Rounding up to the next fuse size gives us 7.5A.

2.3 – Popular 12V Devices for Campers

Below is a list of popular 12V devices installed in camper vans and RVs.

  • LED lights:  These 12V puck lights are popular in the van life community. But light strips and fairy lights are also common.
  • Ventilation fans: Proper ventilation is a must for van life. The Maxxfan and FANtastic Fan are the two most popular models.
  • USB sockets: We like these USB/12V combo sockets. The number of electric devices that can be plugged into these two types of sockets is virtually endless.
  • Fridges: Our electric fridge-cooler is a top-three van life essential for us. Read 6 Reasons To Get An RV Fridge and our Dometic Fridge review to learn more.
  • Water pumps: Pumps water from your fresh water tank to the faucet.
  • Fuel heaters: Whether a heater runs on diesel, gasoline, or propane, it will require a 12V connection to the batteries.
  • Composting toilets: Several professionally made composting toilets, like Nature’s Head, include a small 12V fan to exhaust the bad air.

2.4 – Additional 12V-Related Reading

By now, you should be able to connect all the 12V devices to your battery bank through the bus bars. For more detailed help and explanations related to 12V system installations, check out the following articles.

Chapter 3:

The 120V AC Inverter System

The 12V power supplied by the batteries will not be enough to run many common household appliances and laptops. You will need an inverter to convert the voltage from 12V to 120V. This is the second “power out” section of a camper van’s electrical system.

Note: For readers in Europe, Australia, or Asia, replace 120V with 230V.

What can you power with 120V? Lots of things! If an electrical device has a “normal” plug that inserts into a household socket, it likely requires 120V power.

Diagram illustrating a battery providing 12V power to an inverter, which in turn provides 120V power to various household appliances, like an induction stove and water kettle.
If it’s used in your house, it likely requires 120V.

This section will help you answer the following questions:

  • What size inverter do you need?
  • What size wires are required?
  • How do you install an inverter and all related components?

3.1 – Inverters vs. Inverter/Charger Combos

Before choosing an inverter, you’ll need to decide whether to get a standard inverter or an inverter/charger combo unit.

Standard inverters take 12V power and convert it to 120V power. For these units, electricity only flows in one direction. Inverter/chargers can take 120V power (from an external socket) and convert it back down to 12V to charge the batteries.

Inverter chargers also covert voltage ‘backwards’ from 120V to 12V

Selecting an inverter/charger model will cost you extra and can often cost twice as much as a standard inverter.

Our Opinion: If your budget allows, get an inverter/charger. Charging from shore power is a great backup option when solar power and alternator charging can’t meet your energy demands (i.e., during winter or when parked in shade).

3.2 – Inverter Sizing

It is essential to get the right size inverter to meet your energy demands. If you select an inverter too small, some larger appliances may not function properly.

A graphic showing how larger inverters can power a wider range of 120V AC electrical devices.
More watts = powering larger appliances

Inverter Size Calculator

To help you quickly identify what size inverter best suits your camper van’s electrical system, fill out our calculator form below.

First, you will need to have a general idea of what devices you want to power. Then, you must decide if you want your inverter to charge your batteries from shore power (i.e., an inverter/charger combo). This is a nice feature to have, but these types of inverters are more expensive.

Inverter Size Recommendation

Low: Just to charge a couple laptops, a camera, or power a small blender.

Medium: Includes powering an espresso machine, hair dryer, Instant Pot, or rice cooker.

High: Includes powering an electric hot water heater, microwave, or air conditioner.

3. Recommendation

AIMS | 1000W Inverter & Charger

A popular and well-built inverter for powering small AC devices like laptops and blenders. This unit will also charge your batteries when connected to shore power.

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Manual Calculation

Calculate the maximum wattage your AC loads will draw to identify your ideal minimum inverter size. Don’t add the wattages of AC loads together if you don’t plan to use two certain appliances simultaneously (like a hair dryer and blender). Then, add 20% to your max wattage draw and round up to the next thousand.

Example: Perhaps you plan to run your laptop (~100W) and an InstantPot (~850W) simultaneously. The max wattage from your AC loads is 950W. Adding 20% to this gives 1,140W. Rounding up to the next thousand results in a 2000W inverter.

3.3 – Inverter Installation Guide

This section provides a step-by-step guide to installing an inverter in a camper van, including all the intermediate parts you’ll need. The finished result should look like the diagram below.

Complete inverter wiring diagram. An inverter is connected to the bus bars via a fuse. The inverter is also connected to a circuit panel and two wall sockets.
Complete inverter wiring diagram

Note: For information on how to wire an inverter/charger combo to a shore power source, scroll down to Chapter 6.

A lot is happening in the above diagram, including many different components and wire sizes. To help you better understand this wiring diagram, we separated this inverter installation guide into three parts.

  • Part 1: Wiring the inverter to the bus bars
  • Part 2: Wiring the inverter to power outlets
  • Part 3: Wiring the inverter to ground

Have tiny 120V power requirements?: If you only need a small amount of 120V AC power (e.g., charge a laptop only), you DO NOT need to install an inverter. Scroll down to read about portable “plug in” inverters and see if these units provide a better solution for you.

Do you just need the components? Our inverter parts list post has an itemized breakdown and video product reviews.

Part 1: Wiring the Inverter to the Bus Bars

The first step in the inverter wiring process is to connect the inverter to the batteries. Because we already connected the batteries to the bus bars in Chapter 2, we only need to connect the inverter to the bus bars to complete the circuit. Once this wiring is complete, the inverter can draw 12V power from the batteries to convert it into 120V power.

Refer to the below wiring diagram to see how to complete Part 1 of the inverter installation.

Inverter wired to bs bars via an ANL fuse.
Wiring an inverter to the bus bars via an ANL fuse

Note: Though the above diagram uses 2/0 AWG wire and a 300A fuse, the specific sizes you’ll need for your system depend on the wattage rating of your inverter. We cover these different sizing options after this diagram.

Recommended Wire Size

Before completing this step, you must know what size inverter you will install—the more powerful the inverter, the thicker the wires you’ll need. Locate your ideal wire size from the list below.

  • 1000W inverter: 1/0 AWG wire
  • 2000W inverter: 2/0 AWG wire
  • 3000W inverter: 4/0 AWG wire

Just like in previous sections of this electrical guide, we continue to recommend thick electrical wires from Windynation. Constructed from 100% pure copper conductors and encased in a thick EPDM insulation jacket, Windynation’s USA-made cables are hard to beat.

1000W Inverter
2000W Inverter
3000W Inverter

55mm²

70mm²

120mm²

1000W Inverter
2000W Inverter
3000W Inverter
Recommended Fuse Size

The size of the fuse depends on the size of the wire you selected earlier. Refer to the list below to identify the ideal fuse amp rating based on your wire size.

  • 1/0 AWG wire: 200A ANL fuse
  • 2/0 AWG wire: 300A ANL fuse
  • 4/0 AWG wire: 400A ANL fuse
Recommended Lug Terminals

You will need lug terminals to connect the wire to the inverter, fuse, and bus bars. In the previous wiring diagram, we color-coded our lug terminals (orange and peach color) to help you identify which ring diameter size you’ll need to connect to each component.

If you use 2/0 AWG wire, the lug terminals below are the ones you will need to complete in part 1 of the wiring section.

Part 2: Wiring the Inverter to the Power Outlets

Every inverter has an ‘AC Out’ section, where the 120V ‘AC’ power exits the inverter and is distributed to all the van’s power outlets. This section covers how to connect electrical wire from the inverter to a circuit breaker (and box) and then to all the downstream sockets.

Note: Many inverters (e.g., Renogy & AIMS) already come with sockets built into their enclosures. With these models, you can skip the complicated wiring and plug your AC electrical devices (or power strip) directly into these outlets.

An inverter with two power outlets built into the frame of the inverter.
The AIMS 2000W inverter

Wiring an inverter to your own outlets, however, allows you to integrate sockets into your camper van’s walls or cabinets, which gives your van a more home-like feel. This section will help you achieve this.

After completing Part 2, the result should resemble the diagram below. We will connect the ‘AC Out’ portion of the inverter to the circuit breaker and then wire the breaker to the power outlets.

An inverter wired to two power outlets via a circuit breaker panel.
Wiring inverter to power outlets

In the following sections, we’ll cover appropriate wire sizing and recommended components.

Recommended Wire Size

There are two circuits of electrical wire to pay attention to when connecting an inverter to the power outlets. We’ve noted both circuits in the above diagram.

  1. Feeder circuit: Inverter to the breaker box (feeder circuit)
  2. Branch circuit: Breaker box to the sockets (branch circuit)
Feeder Circuit

The wire size for the feeder circuit (inverter to breaker box) depends on the size of your inverter. This is because inverters that can output greater amounts of watts will require thicker electrical wire to keep the circuit safe from overheating. Refer to the list below to locate your ideal feeder circuit wire size.

  • 1000W Inverter: 12 AWG wire
  • 2000W Inverter: 10 AWG wire
  • 3000W Inverter: 8 AWG wire
Branch Circuit

No matter the size of your inverter, we recommend connecting the circuit breaker box to each power outlet with 12 AWG wires. IMPORTANT: To ensure electrical safety, we recommend wiring each circuit breaker to only one pair of power outlets. If you plan to have two pairs of sockets in your van, plan to have two circuit breakers.

Recommended Wire

Electrical cables for 120V AC power are called ‘triplex wire’ because they comprise three separate inner wires encased in an outer insulation jacket. Inside this outer jacket are the following three wires:

  • Hot wire (black)
  • Neutral wire (white)
  • Ground wire (green)

No matter which wire size you need, we recommend Kimbluth’s triplex wire. These pure copper stranded wires resist all types of corrosion and driving vibration. We use them in our van and are satisfied with their durability.

Recommended Components

Below are the four components we recommend for connecting the inverter to the power outlets. The breaker box we recommend below holds two circuit breakers, which is enough for two pairs of power outlets.

 
 
 
 

This 15A breaker protects 12 AWG wires from overheating.

Holds up to two 15A circuit breakers.

Protects the backside of the power outlets.

One of many standard wall socket designs.

This 15A breaker protects 12 AWG wires from overheating.

Holds up to two 15A circuit breakers.

Protects the backside of the power outlets.

One of many standard wall socket designs.

Part 3: Wiring The Inverter To Ground

The last step is to connect the inverter to a designated ground point on the van’s chassis.

Inverter connected to a designated ground point.
Ground Wire Size Recommendation

The size of the ground wire you will need depends on the size of your inverter. The list below will help you identify your ideal wire thickness based on the size of your inverter.

  • 1000W inverter: 6 AWG wire
  • 2000W inverter: 4 AWG wire
  • 3000W inverter: 2 AWG wire
Lug Size Recommendation

The lug sizes you’ll need to connect the ground wire to the inverter and chassis will depend on your inverter and vehicle model. We recommend this lug terminal variety set to ensure you have the required sizes. This set is also helpful for other parts of the electrical system (e.g., 12V, solar, & alternator charging).

Sanuke | Lug Terminal Set

Save money with this convenient lug terminal set. It covers 12 different lug sizes from 2-8 AWG wires and M6-M10 ring diameters. Heat shrink is also provided.

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How To Locate A Ground Point

Your van’s user manual should help you identify a point on the vehicle’s chassis appropriate for grounding the inverter. Below is an excerpt from our Ford Transit’s handbook indicating the location of all 35 ground points.

Ford Transit ground points on the chassis
Ford Transit ground points

Learn More: How To Wire An Inverter In A Camper Van

3.4 – Portable Inverters

For many van conversions, it isn’t necessary to hardwire a large, bulky inverter. Why invest in a 1000W inverter (and all necessary wires and components) if you only want to power a laptop (65W), small blender (250W), or mini rice cooker (200W)?

That’s why portable inverters provide fantastic value to those with modest 120V AC power needs. The inverter we recommend below provides up to 500W of 120V power and requires NO INSTALLATION. When needed, you take the inverter out from storage and plug it in. When finished, unplug the inverter and store it away.

Great Pickup
BESTEK | 500W Pure Sine Inverter

Plugs into any 12V socket and delivers up to 500W of 110V AC power. Space efficient and packs away when not needed.

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Electrical safety caveat: The portable inverter we recommend above can be plugged into a standard 12V port (aka a “cigarette outlet”) or can connect directly to the batteries via the included alligator clips. If you intend to draw more than 120W of power from the inverter, you must use the alligator clips instead of the 12V port. Drawing too much power through the 12V port can be a fire hazard.

Chapter 4:

Solar Panel Charging

Relying on solar panels is the best way to charge your batteries daily, and installing them is worth the investment. If you’re on a tight budget, you can build a complete solar system for less than $450.

This chapter will cover the following topics:

  • Popular types of solar panels.
  • Calculating your ideal solar size.
  • What size charge controller and wires you’ll need.
  • How to install the solar panels with all required parts and components.

By the end, you’ll have a robust solar charging system that avoids many of the common solar installation mistakes that first-time van converters experience.

4.1 – Types of Solar Panels

One rigid solar panel and one flexible solar panel.

When building a solar system for a camper van, there are two types of solar panels to choose from.

  • Rigid panels: These are the most popular solar panels for van conversions because of their durable construction, which includes a rigid aluminum frame and a top layer of tempered glass that resists scratches and impacts.
  • Flexible panels: These panels are much thinner than their rigid counterparts and do away with the thick aluminum frame. As a result, these solar panels are highly flexible and have a lower profile, which makes them ideal for stealth camping.

Rigid vs. Flexible Solar Panels

This section compares the primary differences between rigid and flexible solar panels and which we ultimately recommend.

Comparison Table
Rigid PanelsFlexible Panels
Efficiency118-22%14-20%
DurabilityStrong
(tempered glass top layer)
Weak
(prone to scratches)
Warranty210 years35 years4
Weight14.1 lb (6.4 kg)5.3 lb (2.4 kg)
Thickness1.4 in (35 mm)0.1 in (3 mm)
Less Visible/Yes
InstallationRequires drilling holesVHB tape only = OK
Price ($/watt)CheaperMore expensive
Better Deal?Yes!

Table Footnotes:
1. Flexible panels are 10-25% less efficient due to heat build-up in solar cells.
2. Renogy warranty information
3. Renogy 100W rigid panel
4. Renogy 100W flexible panel

Rigid vs. Flexible Panels Key Takeaways

Based on the table above, we break down the three most consequential issues when comparing rigid and flexible solar panels.

  • Efficiency: Flexible panels are 10-25% less efficient at converting sunlight into usable energy. The biggest reason for this is that solar cells become less efficient the hotter they get, and flexible panels, with their plastic layers, cannot dissipate heat as well as rigid panels. This means you will need more watts (larger panels) if you choose flexible solar panels.
  • Lifespan: Flexible panels, with their plastic protective layers, are significantly more prone to physical damage (e.g., scratches and cupping) and overheating. Solar manufacturers know this, which is why flexible panels have a shorter warranty than rigid panels (5 vs. 10 years).
  • Installation: Due to their lightweight nature, flexible panels can be mounted on a van’s roof using regular duct tape. Rigid panels, however, should be screwed down, which requires drilling holes.
  • Stealth factor: Flexible panels are less than 1/10th the thickness of rigid panels, making them ideal for stealth campers.

Solar Panel Recommendations

We recommend rigid solar panels for the vast majority of camper van conversions. With their tempered glass top layer, rigid panels are more resilient to the daily rigors of van life. They’re also more likely to last longer (we’ve seen several flexible panels go bust after less than a year of use), which is evident with their longer warranty periods.

We installed Newpowa solar panels on our camper van, and they have been working for us non-stop for the past five years. Our panels have frequently brushed up against low-hanging branches and have been covered in dirt and bird poop. But after a quick wipe-down, our panels still look like new. Newpowa panels tend to be the most affordable ($ per watt) compared to other brands, but you should double-check on Amazon.

Newpowa | Solar Panel (200W)

We use Newpowa panels on our van, and they've been working great for over five years of van life. Newpowa also tends to sell the lowest cost panels, dollar-per-watt.

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To learn more, read our more thorough solar panel comparison for campers.

4.2 – How Much Solar Do You Need?

A common misconception when sizing a solar system is that “solar panels power electrical devices.” This leads people to only look at the size of their electrical loads and solar watts. But this view is incomplete because it doesn’t factor in battery size.

Example: Suppose you have a large electrical system and installed a correspondingly large solar system. But if your batteries are undersized, they won’t be able to sustain the large electrical load in the evening when the solar panels are unproductive.

Three solar panels feeding power to only one battery, which is power a wide array of electrical devices.
Battery may not support loads at night (or on cloudy days)

Over the years, we’ve seen this situation more often than you would think in actual camper vans. So, what’s a better way of going about this? Instead of sizing the solar panels to your electrical load, think about sizing your solar panels to your batteries and sizing the batteries to the load. In this way, the batteries will be able to support the loads during the daytime AND night, and the solar panels will be able to recharge the batteries sufficiently the next day.

Side by side comparison graphic of one solar panel, one battery, and a several loads next two two solar panels, two batteries, and a larger set of electrical loads.

Consequently, we recommend the below two-step process for sizing your solar system.

  • Step 1: Calculate battery size based on electrical load (use battery calculator)
  • Step 2: Calculate solar size based on battery size

Solar Calculator

Once you’ve used our battery calculator to size your battery bank, download our solar calculator (below) to identify your ideal solar wattage size. If you fill in all the fields, the calculator will ALSO recommend the correct size wires, charge controller, and fuses.

For a step-by-step calculator tutorial, read: How to calculate your solar panel size

Battery/Solar Table

We think our solar calculator is pretty nifty. But if you’d prefer not to download any files, refer to our solar size table below. If you have a 12V battery bank, use the ratios below to determine your solar array wattage size.

  • Lithium batteries: Use a 1:1 ratio of battery bank Ah to solar array watts.
  • AGM batteries: Use a 2:1 ratio of battery bank Ah to solar array watts.
12V Battery Size (Ah)Solar Watts (with AGM)Solar Watts (with Lithium)
100Ah50W100W
200Ah100W200W
300Ah150W300W
400Ah200W400W

Have a 24V system? Use a 1:2 ratio for lithium batteries and a 1:1 ratio for AGM batteries.

4.3 – Series vs. Parallel Panel Wiring

Just as when wiring batteries together, you can choose to connect multiple solar panels either in series or parallel. The graphic below shows the wiring differences between the two styles.

Two solar panels wired in series and two solar panels wired in parallel
Series vs. parallel solar panel wiring

Although both wiring methods will yield the same total watts under the same intensity of sunlight, there are subtle outcome differences you should know to help you make an informed decision as to which approach to use. Our table below highlights these differences.

SeriesParallel
Total current (A)Remains sameAdds up
Total voltage (V)Adds upRemains same
Wire sizeSmallerLarger1
Charge controller sizeSmallerLarger1
InstallationEasierMore complex2
Performance in shadeWoseBetter3

Table Footnotes:
1. Most times larger, but not always.
2. Requires branch connectors & (sometimes) solar fuses.
3. Better wattage output in partial shade

Key Takeaway

It is up to you to decide how to connect your solar panels. Panels wired in parallel are more efficient when partially shaded but require additional components (branch connectors), and you ‘might’ need to install additional fuses.

Our opinion: If you only have two solar panels, connect them in parallel for added efficiency in the shade. Two panels in parallel do not need to be fused. If you have three or more panels, consider wiring them in series for a simplified wiring process without fuses or bulky branch connectors.

Learn more: Series vs. Parallel Solar Panel Wiring

4.4 – Solar Charge Controllers

Solar charge controllers are voltage regulators that receive uncontrolled voltage from the solar panels and feed the batteries a steady, controlled voltage for proper charging. Without a charge controller, the voltage received from the solar panels would damage the battery.

A solar panel sending uncontrolled voltage to a solar charge controller, which then sends a regulated voltage to the battery.

Think of your brain as the charge controller while you’re eating. As you eat, you become more full, and your brain tells your body to slow down your eating speed. When you’re full, your brain tells you to stop eating. Without the brain telling you when to slow down and eventually stop eating, you’d continue to eat until…bad things happen. The same would be true for a battery that is connected to a solar panel without a charge controller.

What Size Solar Charge Controller Do You Need?

Charge controllers come in different sizes (amp-ratings). The more watts a solar array produces, the larger the charge controller will need to be. Based on your solar array’s total wattage, use the list below to find your ideal charge controller size.

  • 0-220W: 15A controller
  • 220-440W: 30A controller
  • 440W-700W: 50A controller
  • 700-1000W: 70A controller

Our Opinion: We love our Victron-branded charge controller. All models are Bluetoo-enabled and allow us to view our solar harvesting stats directly from our smartphones. Read our Victron charge controller review to learn more.

For more detailed info, read: What size solar charge controller do you need?

4.5 – Solar Installation Guide

This section covers all the wires and components required to install a solar charging solution for your camper van’s electrical system. Your solar system should eventually resemble the diagram below.

Complete wiring diagram for camper vans and RVs connecting the solar panels to the bus bars via various components such as circuit breakers, solar charge controller, and an entry gland.
Complete solar wiring diagram for camper vans

A lot is happening in the above diagram, including many different components and wiring. So, to help you better make sense of this wiring diagram, we separate this solar installation guide into two parts.

  • Part 1: Wiring solar panels to the charge controller
  • Part 2: Wiring charge controller to the bus bars

Do you just need the components? Visit our solar parts list post for an itemized breakdown with video product reviews.

Part 1: Wiring the Solar Panels to the Charge Controller

This first part focuses on connecting the solar panels to the solar charge controller. We will cover the wire sizes you need and all additional components required to complete this wiring section.

Below is the wiring diagram we will use to connect the solar panels to the charge controller. This diagram is accurate for solar arrays up to 440 watts.

Wiring diagram connecting the solar panels to the solar charge controller via MC4 connectors, an entry gland, a rubber grommet, and a solar breaker.
Recommended Wire Size

Getting your solar wire size correct is mission critical for solar safety. If you want to understand the theory and details involved, read our solar wire size guide. It is a fantastic resource. Below, we provide a summary.

Correctly sizing the wires from the solar panels to the charge controller involves a two-part process:

  • Part 1: Calculate the maximum current output of the solar array.
  • Part 2: Multiply max current by 1.56 for NEC safety factor (NEC 690.8)

Example: Two solar panels wired in parallel, each with a short-circuit current of 11.75A, have a maximum current output of 23.5A (11.75A + 11.75A). Multiplying 23.5A by 1.56 gets us 36.7A.

Below is a summary table of recommended solar wires based on the amperage figure you calculated after the 1.56 NEC safety factor.

Solar Array Amps (After 1.56x Factor)Solar Wire Size1
30A (or less)12 AWG
30A-40A10 AWG
40A-55A8 AWG

Table Footnotes:
1. Based on Windynation ampacity ratings

Based on the solar wire sizes above, we recommend the below Windynation solar connectors, which are USA-made and UL certified. These wires already come with MC4 connectors crimped on both ends. We prefer these wires because the jackets are UV/sunlight resistant, which is essential for solar cables placed on the vehicle’s roof.

Note: For wires longer than 20 feet, consider upgrading to one size larger to prevent voltage drop and power loss.

Recommended Components

We recommend the following four components to complete this wiring section. You can identify the location of each component in the above wiring diagram.

 
 
 
 

Crimps onto 10 AWG solar wires.

Prevents water leaks as wires pass through vehicle roof.

Inserts into drill holes. Protects wires from chaffing.

Protects 10 AWG solar wire from overheating.

Crimps onto 10 AWG solar wires.

Prevents water leaks as wires pass through vehicle roof.

Inserts into drill holes. Protects wires from chaffing.

Protects 10 AWG solar wire from overheating.

Part 2: Wiring the Charge Controller to the Bus Bars

This second part focuses on connecting the solar charge controller to the bus bars. We will cover the wire sizes you need and all additional components required to complete this wiring section.

Below is the wiring diagram we will refer to when wiring the charge controller to the bus bars. This diagram is accurate for solar arrays up to 440 watts.

Wiring diagram connecting the solar charge controller to the bus bars via a circuit breaker.

For information on connecting the bus bars to the 12V batteries, scroll up to view the wiring diagram from Chapter 2.

Recommended Wire Size

The wire size you’ll need to connect the charge controller to the bus bars depends on the ampacity rating of your charge controller. The larger the controller, the thicker the wire. Scroll up to learn what size charge controller you need.

Once you have your charge controller, multiply its ampacity rating by 1.25 (NEC 25% rule). Finally, find your ideal wire size based on the range that your charge controller belongs to (after the 25% rule).

Charge Controller Size (Amp Rating)Wire Size1
0-30A10 AWG
30-55A8 AWG
55-115A6 AWG
115A-150A4 AWG

Table Footnotes:
1. Size recommendations based on Windynation certification

The below wires (8 AWG to 4 AWG) are Windynation wires, which we trust to carry the ampacity ranges we list in the above table. The 10 AWG wire below is an Ancor marine-grade wire, a brand that we also trust.

Recommended Components

Below are the three components you’ll need to complete this section.

1. Circuit Breaker

The amp rating of the circuit breaker you need depends on the size of the wire you are using. Refer to the list below to identify your ideal circuit breaker size.

  • 10 AWG wire: 30A breaker
  • 8 AWG wire: 40A breaker
  • 6 AWG wire: 70A breaker
  • 4 AWG wire: 100A breaker

For more info, read: How to fuse a solar array.

2. Lug Terminals

The circuit breaker and bus bars accept 1/4″ and 3/8″ ring sizes, respectively. The neck size of the lugs depends on the wire size you are using. We recommend buying an assorted lug set, which will have the lugs you need and will also be useful for other parts of the electrical system.

Two lugs side by side indicating the two different sizes you will need to complete this solar wiring step.
3. Bus Bars

The bus bars receive the power from the solar panels via the charge controller and send the power back to the batteries for charging.

 
 
 

Protects 8 AWG wire from overheating

Allows solar wire to connect to breaker and bus bars.

Power collection and distribution centers.

Protects 8 AWG wire from overheating

Allows solar wire to connect to breaker and bus bars.

Power collection and distribution centers.

For a more detailed tutorial, read: Solar installation guide for camper vans.

4.6 – Mounting Solar Panels on the Roof

Before hoisting your solar panels onto your van’s roof, there are two things to consider.

Solar Panel Layout

Will you be laying out your solar panels length-wise or width-wise? And which way is the most space-efficient?

Laying solar panels lengthwise vs. widthwise on a camper van roof
Solar panel layout options on van roof

To answer these questions, you’ll need to know the size of your solar panels and the dimensions of your van’s roof. Then, you can play around with different configurations to help you choose the best fit.

To learn more, read: Solar panel roof layout design.

Direct Mount vs. Roof Rack

Will you be installing the solar panels directly onto your van’s roof with screws and silicone sealant? Or will you install a roof rack first?

  • Direct mount: Installing rigid panels directly onto your van’s roof (with screws) will give your solar panels the lowest profile and make them less visible from the street. This is the stealthier option. The downsides are that you will create holes in your van’s roof (leak potential), and removing the panels for maintenance will be a hassle.
  • Roof rack: All roof racks increase public awareness of your camper but offer a less invasive installation process for your panels. Unaka Gear Co has a wide range of roof racks for Sprinter, Transit, & Promaster vans.

Our experience: We installed the solar panels directly on our van’s roof. They’ve worked great, look streamlined, and we haven’t had any leaks (yet). But if we could do our build again, we’d spend the money on a low-profile roof rack instead.

Direct Mount Materials

If you decide on the direct mount method, we recommend the three materials below to help ensure an extra strong, leak-proof connection between the solar panels and roof.

Learn more: How to mount solar panels a van’s roof (without leaks).

Chapter 5:

Alternator Charging

Charging auxiliary batteries from the vehicle’s alternator is another essential method for providing power to your camper van’s electrical system. In fact, solar AND alternator charging should be your “one-two punch” for ensuring your batteries never run out of power.

5.1 – What Is Alternator Charging?

A vehicle’s engine converts gasoline (or diesel) into movement energy via a drive belt that propels the vehicle forward. An alternator is a generator that attaches to the engine’s drive belt and converts movement energy into electrical energy. The alternator’s purpose is to keep the vehicle’s starter battery charged and to power all the internal electronics in the van, such as the radio, headlights, and power windows.

A vehicle's engine providing kinetic energy to an alternator, which converts it to electrical energy and charges the starter battery.

With an intermediary device, like a DC-DC charger or a split charge relay, you can direct some of the power that the alternator generates to charge the auxiliary battery. If you have this system set up, your batteries will receive a charge as long as the vehicle’s engine is running.

5.2 – Split Charge Relays vs. DC to DC Chargers

Charging an auxiliary battery from the alternator is more complicated than simply hardwiring the two parts together. Doing so would quickly drain your starter battery and, if you had a lithium battery, the alternator would not provide a proper charge. That is why you need a split charge relay (SCR) or a DC-DC charger to manage the power from the alternator to the battery.

Both devices are similar in that they sense when the alternator is engaged and siphon power designated for the starter battery to the auxiliary battery. Split charge relays are cheaper to buy, but they come with restrictions.

  • Not recommended with many modern vehicles. Newer vehicles have ‘smart alternators’ that automatically regulate the voltage output. This is good for power efficiency (and environmental regulations), but this varying voltage confuses the split charge relay, which leads to an inefficient auxiliary battery charge.
  • Not recommended with lithium batteries. When activated, split charge relays connect the starter battery (lead-acid/AGM) with the auxiliary battery. If the auxiliary battery is lithium-based, the relay will be connecting two batteries with different chemistries. This leads to problems like sub-optimum charges of the lithium battery – due to different battery charge profiles – and overworking the alternator – due to the lithium battery’s lower internal charge resistance.

Comparison Table

DC-DC ChargersSplit Charge Relays
CostMore expensiveCheaper
OK with modern alternators?YesNo
OK with AGM batteries?YesYes
OK with lithium batteries?YesNo
Popular modelVictron OrionVictron Cyrix-ct
Which do we prefer?Yes!

Although DC-DC chargers are more expensive, we highly recommend them if you are serious about building a robust camper van electrical system. We’ve already established, back in Chapter 1, that lithium batteries are substantially better than AGM batteries, and that reason alone is enough to invest in a DC-DC charger.

5.3 – What Size DC-DC Charge Should You Get?

DC-DC chargers are listed by their amp rating, which is the maximum amps that the charger can output into the auxiliary batteries. The higher the amp rating, the more amps output, leading to a faster battery charge. For example, in a 12V system:

  • 18A charger = 220W charging
  • 30A charger = 360W charging
  • 40A charger = 480W charging

You decide the amp rating of your DC-DC charger. Typically, the higher the amp rating, the more expensive the charger. We recommend Victron-branded DC-DC chargers because they come Bluetooth-enabled, meaning you can view all your battery charging stats directly on your smartphone. We personally use Victron’s 30A charger and have been satisfied with the quality.

Good to know. Since the alternator is now charging two batteries (starter & auxiliary) there is additional strain placed on the unit. The greater than amp rating of the DC-DC charger, the more stress the alternator experiences and, ultimately, the shorter the lifespan. But for most people, us included, this trade-off is worth it.

5.4 – Alternator Charging (DC-DC Charger) Installation Guide

This is arguably the easiest wiring section of all the chapters we cover. By the end of this chapter, you should have a wiring system that resembles the diagram below.

Complete alternator charging wiring diagram including a DC-DC charger, starter battery, and bus bars.

For information on connecting the bus bars to the 12V batteries, scroll up to view the wiring diagram from Chapter 2.

We’ll discuss each component in the above diagram, but if you just want a quick list, see our DC-DC charger parts list.

Recommended Wire Size

For 12V systems, which we recommend in Chapter 2, Victron recommends using 6 AWG wires when installing their 18A & 30A DC-DC chargers. Below is an excerpt from the Victron Orion manual assigning 16mm2 wire (6 AWG) for cable lengths between 5 and 10 meters.

Victron Orion DC-DC charger user manual excerpt indicating 6 AWG wire size recommendation.

We love electrical wires from Windynation, which are made in the USA. They are 100% pure copper wires with an exceptionally high strand count for ultra-flexibility and resistance to driving vibration. Windynation’s 6 AWG wires are what you’ll need.

Windynation | 6 AWG Wire

Recommended size for DC-DC chargers. These 100% pure copper stranded wires are what you'll need. Perfect for high amperage environments (up to 115A)

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Using Renogy’s 40A charger? Use 4 AWG wires instead (per Renogy’s manual)

Recommended Fuse Size

Referring to the same Victron Orion table below, we can see that the manufacturer recommends a 60A fuse. So this is the size we recommend.

Victron Orion DC-DC charger user manual excerpt indicating 60A fuse size rating.
Use A Fuse Or Breaker?

Both fuses and circuit breakers are designed with the same end purpose: to protect the circuit wiring from overheating and catching on fire. Fuses are cheaper and are generally recommended by DC-DC charger manufacturers in their manuals.

However, between our DC-DC charger and the bus bars, we substituted the fuse with a 60A circuit breaker instead. This is not essential, but we wanted to manually disconnect the circuit for whatever reason, including long-term vehicle storage and when conducting electrical maintenance.

Starter Battery to DC Charger
DC Charger to Bus Bars
Starter Battery to DC Charger

Recommended Lug Sizes

If you follow our DC-DC charger wiring diagram, you will need lugs with a 6 AWG neck size and 3/8″, 5/16″, and 1/4″ ring diameters. We color-coded our lugs to help you identify which lug sizes go where.

  • 60A circuit breaker: 1/4″ lug
  • 60A fuse: 5/16″ lug
  • Bus bars: 3/8″ lug
Three lugs with a neck size to fit 6 AWG wires. One lug with a 3/8" ring diameter, another with 5/16" ring diameter, and another with 1/4" ring diameter.

Since there are three different lug sizes, buying an assorted lug set is the most convenient and affordable. The set we recommend below will have the lugs you’ll need to complete this section AND the other parts of your camper van’s electrical system.

Sanuke | Lug Terminal Set

Save money with this convenient lug terminal set. It covers 12 different lug sizes from 2-8 AWG wires and M6-M10 ring diameters. Heat shrink is also provided.

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For more information, read: How to install a DC-DC charger in a camper van

Chapter 6:

Shore Power Charging

Charging from shore power entails connecting your auxiliary batteries to an external socket via a battery charger. External sockets are most commonly located at campsites, RV parks, and at your own home. If lucky, you can find a socket on the side of a gas station convenience store (nice!).

This section covers what you’ll need to know about charging your battery from shore power, including required devices, socket types, and how to integrate a charging solution into your camper van’s electrical system.

6.1 – How To Charge From Shore Power

Since shower power supplies 120V power, and batteries require 12V power, you will need a battery charger that down-converts the incoming voltage and supplies the power at a rate suitable for charging a battery. These voltage-converting battery charges typically come in two options.

  • Inverter/charger combo units
  • Dedicated chargers

Inverter/Charger Combo Units

In Chapter 3, we learned that inverters convert power from 12V to 120V to run standard household devices. Some inverters, however, have a built-in battery charger feature that ALSO converts power from 120V back to 12V. These inverter/charger combo units are convenient, but they tend to be more expensive than standard inverters.

One noticeable difference between an inverter and an inverter/charger is the presence of an “AC In” port. This is the port where 120V AC power enters the inverter/charger.

Dedicated Battery Chargers

These chargers typically convert voltage in one direction only (120V to 12V) and are dedicated to charging auxiliary batteries from shore power. Since these devices already come with a corded plug to be inserted into an external socket, installation is relatively quick and straightforward, unlike an inverter/charger, which requires DIY wiring to the AC In ports.

Comparison Table (Dedicated Charger vs. Inverter/Charger)

Below, we compare the three most significant differences between dedicated battery chargers and inverter/charger combo units.

Dedicated ChargerInverter/Charger Combo
Price1CheaperMore expensive
Installation2EasierMore complex
Total area footprint3LargerSmaller

Table Footnotes:
1. Lots of affordable options at slower charge speeds
2. Inverter/chargers will require wiring and power inlet installation
3. Assumes you also install an inverter. Combo units save space.

Key takeaways: If you’re on a tight budget, dedicated battery chargers provide a shore power charging solution for as little as ~$60. But if you have more financial flexibility, consider an inverter/charger combo unit.

6.2 – Recommended Battery Chargers

We use a Victron Multiplus inverter/charger in our camper van. It is a 2000W inverter with an 80A (960W) charger. The Multiplus is not the cheapest option, but it is a well-built unit that’s handled five years of daily use and survived thousands of miles of pristine highways and hellish, pitted dirt roads throughout North & South America.

Victron’s Blue Smart charger is a good bet if you’re looking for a dedicated charger. Though we do not have personal experience with this unit, we did have a cheap charger before, which broke down after only a month of use. So, we can’t recommend any of the cheaper “no frills” chargers on Amazon.

Dedicated Charger
Inverter/Charger Combo

Simple dedicated battery charger to recharge batteries from shore power.

Powerful 2000W inverter/charger combo unit. We use this unit in our camper van.

Dedicated Charger

Simple dedicated battery charger to recharge batteries from shore power.

Inverter/Charger Combo

Powerful 2000W inverter/charger combo unit. We use this unit in our camper van.

6.3 – Shore Power Charging Install Guide

This section provides a step-by-step guide for installing an inverter/charger combo to shore power and the auxiliary batteries. By the end, you’ll have a shore power charging system that looks like the wiring diagram below.

This install tutorial is separated into two parts:

  • Part 1: Shore power to inverter/charger
  • Part 2: Inverter/charger to batteries
  • Part 3: Dedicated charger wiring

Part 1: Shore Power to Inverter/Charger

This first section covers what you’ll need to connect an inverter/charger to shore power. When completed, you’ll have a system that resembles the wiring diagram below.

Wiring diagram connecting an inverter/charger combo unit to an external shore power socket via electrical wire, a power inlet, and an extension cord.
Connecting an inverter/charger to shore power
Recommended Materials
Triplex Wire

To connect the inverter/charger to the power inlet, you will need triplex wire. Triplex wire has three individual wires (hot, neutral, and ground ) wrapped inside an outer insulation layer. The wire size you need depends on your specific charger’s rated amps. The higher the amps the thicker the wire required.

  • 100A or less: 12 AWG triplex wire
  • 100A – 220A: 10 AWG triplex wire

For most chargers, 12 AWG wire will be the correct size. The 2000W Victron inverter/charger in the above diagram has an 80A battery charger, so we use 12 AWG wires in the diagram.

Power Inlet

The backside of the power inlet is wired to the inverter/charger, and the front is a male socket that will connect to a shore power source via an extension cord. The amp rating of the power inlet depends on the amp rating of the battery charger:

  • 100A or less: 15A power inlet
  • 100A – 220A: 30A power inlet

Another way to think about it is if you are using 12 AWG triplex wire, use a 15A power inlet. If you are using 10 AWG triplex wire, use a 30A power inlet.

Extension Cord

You need an extension cord to connect the power inlet to a shore power receptacle. Beware that many cheaper extension cords available online are assembled with thinner 16 AWG wires and it may be unsafe to transmit large amounts of amps through these cheaper extension cords.

We recommend the following sized extension cords based on the amp rating of your power inlet.

  • 15A power inlet: 12/3 AWG cord
  • 30A power inlet: 10/3 AWG cord

Part 2: Inverter Charger to Batteries

This wiring section is similar to the inverter wiring diagram in Chapter 3. It covers everything you’ll need to connect the inverter charger to the bus bars. When finished, you should have a system that resembles the wiring diagram below.

To learn how to connect the bus bars to the auxiliary batteries, scroll up to our wiring diagram in Chapter 2.

Recommended Wire Size

For inverter/charger combos, when calculating the wire size between the unit and the bus bars, it is better to size the wire according to the inverter than the charger component. This is because the inverter typically demands more amps from the battery than the charger will put back into the battery. Based on your inverter’s wattage rating, we recommend the following wire sizes:

  • 1000W inverter/charger: 1/0 AWG wire
  • 2000W inverter/charger: 2/0 AWG wire
  • 3000W inverter/charger: 4/0 AWG wire
1000W Inverter
2000W Inverter
3000W Inverter

55mm²

70mm²

120mm²

1000W Inverter
2000W Inverter
3000W Inverter
Recommended Fuse Size

The size of the fuse depends on the size of the wire you selected earlier. Once you’ve finalized your wire size, refer to the list below to identify the ideal fuse amp rating.

  • 1/0 AWG wire: 200A ANL fuse
  • 2/0 AWG wire: 300A ANL fuse
  • 4/0 AWG wire: 400A ANL fuse
Recommended Lug Terminals

In the previous wiring diagram, we color-coded our lug terminals to help you identify which ring diameter size you’ll need to connect to each component. You will need a combination of 3/8″ lugs (orange) and 5/16″ lugs (peach).

If you use 2/0 AWG wire, below are the lug terminals to complete the Part 1 wiring section.

Part 3: Dedicated Charger Wiring Diagram

If you are using a dedicated battery charger instead of an inverter/charger combo, this is the wiring diagram you will be following.

Recommended Wire Size and Components

Victron, in their user manual, recommends using 6 AWG wire and a 50A fuse. So these are the components we also suggest. You will also need two different sized lug terminals – 3/8″ and 5/16″ – and you can get these sizes from the lug terminal variety set we recommend below.

Chapter 7:

Appendix and Footnotes

So, you would like to read and learn more about the tiny details of electrical theory and how it pertains to camper van electrical systems! Below is our growing section of essential information to know but couldn’t squeeze into the main body of our electrical guide.

7.1 – General Electrical Wire Information

Wire Thickness vs. Electrical Current

Understanding the relationship between wire thickness (gauge) and electrical current (amps) is essential to electrical safety.

When current flows through a wire, heated is created. When too much current is flowing, the wire eventually gets so hot that it catches on fire. But the thicker the wire, the more amps it can handle before becoming a fire hazard. Consequently, the more current you anticipate a wire experiencing, the thicker the wire you will need.

Here is a wire ampacity chart we often refer to when sizing our van’s electrical wire.

Solid vs. Stranded

Electrical wires can comprise of a single thick metal conductor (aka “solid wire”) or of multiple thinner conductors (aka “stranded wire”) that, together, make up the same gauge as a solid wire.

SolidStranded
Advantages– Cheaper
– Supports higher amps
– Better for long distances
– Increased flexibility
– Less material fatigue from movement
Great for:HomesCamper vans, RVs, boatrs

Key takeaway: for van conversions, you should be buying only stranded electrical wire. The constant movement and vibration that a camper van experiences while driving would weaken the metal conductor and eventually snap a solid wire.

Pure Copper (OFC) vs. Copper-Clad Aluminum (CCA)

Not all electrical wires are constructed using the same raw materials. Some wires consist of conductors made from pure oxygen-free copper (OFC) while others consist of conductors made from aluminum with an outer copper cladding.

Compared to copper, aluminum is a cheaper metal but is a poorer conductor of electricity and cannot safely transmit the same amount of current (amps). As a result, it can be more dangerous to substitute CCA wire for pure copper wire at the same gauge size.

CCA wires also experience mechanical fatigue faster than OFC wires, and so they are more prone to breaking when exposed to frequent movement and vibration.

Note: All our wire size recommendations on this blog assume pure OFC wire. Not only do they conduct the greatest amount of amps at each gauge size, but they are also safer and more appropriate for use inside camper vans.

Marine-Grade Wires

With exposure to salty air and UV light, marine environments can quickly corrode electrical wire. Marine-grade wires were built to better withstand harsher marine environments and meet stricter American Boat & Yath Council (ABYC) wire standards. Their improved construction often includes:

  • Tinned copper: Copper conductors are coated in tin to protect against oxidation and moisture corrosion.
  • Exceptionally high strand count: For even greater flexibility and bending.
  • Higher temperature resistance: Wire jackets are rated for 105° C, which is higher than basic wire standards.

Wire Ampacity Table (Abridged)

Below is a condensed version of a standard wire ampacity chart. We only included the wire sizes relevant to this post and chose the most conservative ampacity rating (temperature rating of 60°C). For a comprehensive table, visit this wire chart.

Wire Size (AWG)Ampacity Rating (@ 60°C)
1415
1220
1030
840
655
470

7.2 – Wire Installation Accessories

Don’t make the mistake of laying out unprotected wire throughout the van. When driving, every inch of the van experiences frequent and acute vibrations, and that includes all your electrical wires. Over time, this vibration – when paired with nearby sharp objects – can wear down and cut through the insulation jackets, exposing the bare metal conductors inside. This can lead to short circuits and fires.

Placing your electrical wires in a wire loom helps protect the wire from excessive friction. Wire looms pair well with zip-tie mounts, which attach to virtually any surface inside a van conversion and prevent the wire loom from flopping around.

7.3 – Windynation Wires

There are A TON of different electrical wires sold online. Some of these wires are good quality, but some are questionable junk with foreign manufacturers facing no real accountability for misleading marketing. Sifting through all the varieties is a headache. We know, we did it ourselves!

To keep this post simple and safe, we only recommend Windynation-branded solar cables. Windynation is an American-based company, and every wire is UL-tested and 100% made in the USA. In other words, we trust their listed wire ampacity ratings, which, in turn, keep our solar system safe.

Solar Wire Connectors (10 AWG, 10 AWG, 8 AWG)

Below are the solar wire specifications for Windynation’s 8 AWG, 10 AWG, and 12 AWG wires. These solar connectors are UL-certified, National Electric Code compliant, and are rated to handle the below-specified ampacities.

The wire specifications of Windynation's 8 AWG, 10 AWG, and 12 AWG solar cables with the ampacity ratings indicated.

Stranded Copper Wires and Cables

We inquired with Windynation support staff regarding the ampacity ratings of their wires and below is an excerpt of their reply.

“Attached is our Certificate of Conformance for our cable. The ampacity is indeed continuous in open air (room temp).”

Windynation Engineering Staff
Excerpt clip from Windynation's certificate of compliance showing the ampacity ratings of their electrical wires.
Ampacity ratings for each wire gauge

Their certificate of compliance is the perfect resource because it verifies Windynation’s own wire ampacity ratings in a continuous current environment instead of relying on a generic 3rd party table that encompasses many different wire grades. We will refer to this certificate when recommending your (section 2) solar sizes.

We also like Windynation because the American-based company manufactures premium-quality pure copper wires encased in a tough EPDM rubber insulation jacket for high-temperature resistance and ultra-flexibility. Lastly, these wires are assembled in the USA, which we prefer because this gives us greater reassurance that we can trust the wire quality and their verified ampacity ratings.

“The cable uses copper mined in Canada and is indeed extruded / stranded in the USA. The copper strands are bundled and wrapped in a paper separator that is then encapsulated in an EPDM rubber jacket.”

Windynation Engineering Staff

7.4 – Recommended Electrical Tools

The following tools are instrumental in building an electric system:

FAQ

Do You Recommend All-in-One Power Stations?

These power stations, like the Bluetti Portable Power Station, are convenient devices that make building a camper electric system quick and easy. And if you have a small, modest-sized electric system and are not inclined to create an entire system from scratch, an all-in-one power station can be a great option.

But convenience comes at a cost. These power stations are relatively expensive for the amount of stored power you buy. You can DIY your own battery bank and have 50-80% more power capacity for almost the same amount of money!

Do You Recommend Electric Water Heaters?

Electric water heaters can be helpful if you have a large enough battery bank and are willing to invest in a 3000W inverter. However, water tanks take up valuable storage space, and we never took enough showers to justify keeping our tank.

Unless you plan to build an indoor shower stall, skipping an electric tank is the smart option. Instead, opt for a solar shower bag. They’re compact, cheaper, and more convenient to use. You can always boil water to fill the bag if the water isn’t hot enough by the end of the day. We use ours ALL THE TIME.

Do You Recommend Induction Stove Tops?

Cooking with electricity (as opposed to using propane) can be a viable option, but only if you have sufficient battery capacity. If using lithium batteries, we recommend having at least 300Ah of battery capacity (at 12V).

How Do You Maintain a Camper Electrical System?

There are three things we like to do to help keep our camper’s electric system in tip-top shape:
Ensure bolts and screws remain tight: Once every few months, we use a screwdriver and socket wrench to tighten any screws and bolts that may have become loose due to vibrations from driving.
Ensure proper battery state-of-charge (SOC): Did you know AGM and lithium batteries like to be kept at different SOCs? For example, AGMs prefer to remain at 100% charge, while lithium batteries prefer to be around 40-80%. Read our battery maintenance post to learn more.
Prepare for long-term storage: When prepping to store the camper for long periods, we shut off our electric system and keep our lithium battery bank at ~50%. We would purchase a battery maintainer (trickle charger) for AGMs to keep them consistently charged at 100%.

Conclusion

We hope you enjoyed reading our camper van electrical system guide and found the information helpful. Building your system takes time and lots of homework, but if you go slow and are careful, we’re confident you can arrive at a successful installation.

If you have any questions on how to install an electrical system in your camper van, please post a comment in the section below.

Happy building!

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2 Comments

  1. I am converting from lead acid to Lithium. I purchased a new inverter and a dedicated charger. Your wiring diagram shows that it will connect to the bus bars. When it is charging it delivers more than 14V to charge the batteries. Since it is attached to the bus bar won’t it also be delivering that same voltage to all of the 12V circuits attached to the bar? If I connect directly to the battery it would bypass the monitor. Confused on how to proceed or am I overthinking it?

    1. Hello Thomas! Yes, don’t overthink it. Sending 14.xx volts to your 12V circuits is OK. We’ve been doing it for 5 years and everything has been fine. Hope this helps!

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