DIY Camper Van Electrical System: An Epic Off-Grid Setup

From batteries, to solar, to 100% FREE electrical diagrams, this post has EVERYTHING you need to set up your own camper van electrical system.

Keep reading to learn more!

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Want to build a robust, off-grid camper van electrical system? You’ve come to the right place! In this post we teach you how to build the very same van electrics wiring diagram that you see below.

Fig 1.1 - Complete Van Electrical System Diagram

We understand. The electrical diagram above is a bit of a mouthful. There are lots of different wires, components, and products; so it can seem overwhelming at first. But take it slowly, section-by-section, and we’re confident you’ll come away with your own functioning electrical system for your van.

There are at least 4 different systems going on in the above wiring diagram.

Our van electrics guide teaches you how to DIY each of these 4 systems.

Our van’s electrical system, the very same as the one above, has:

In this page, you will find everything you need to build your electrical system for a camper van.   

Table of Contents
    Add a header to begin generating the table of contents

    So if you’re ready, let’s get started!

    12v Electrical System


    Starting from the beginning? Learn all about camper van batteries in the section below.

    12v Wiring

    Got your batteries and ready to wire everything together? Let’s get the installation going!

    Batteries For Camper Vans

    AGM vs Lithium - Lithium Batteries Are Better For Us

    The batteries that power your electrical devices are the foundation of any camper van’s electrical system.  These batteries are typically called “house batteries”.

    House Battery vs Starting Battery:
    Although it’s possible to run your van electrics from your starting battery, we recommend purchasing separate batteries to power all your devices.

    In order to buy the batteries you need for your van conversion, you’ll need to answer the following two questions:

    We discuss how you can answer these two questions in our two posts below.

    AGM vs. Lithium Batteries

    When first planning your camper’s battery system, it’s critical to know which type of battery you want to go with. In this article, we discuss the primary differences between AGM and Lithium batteries. The choice is up to you!

    How Much Battery You Need

    We all have different electrical needs. And so our battery capacities can’t all be the same. This article teaches you how to calculate the ideal battery bank capacity to match your lifestyle.

    12v Wiring Process

    12v Wiring Diagram For Camper Vans & RVs
    Complete 12v wiring diagram

    At the heart of any campervan electrics setup is the 12v system. This is because most of the deep-cycle batteries sold here in North America are made to run on a 12v system. Therefore it makes it convenient to run a system that can run directly from the batteries without having to adjust the voltage (i.e. with a 120v power inverter)

    Live Outside North America? If you're in Europe, Australia, or elsewhere, chances are you're looking to run a 24v system instead. If so, this section is still helpful for you. Simply replace 12v with 24v and you should be good to go.

    Learn More About 12v Setups

    How To Build A 12v System

    Step-by-step, this post details how to build your very own camper 12v system. We talk about selecting the right devices, wiring components, and provide intuitive installation diagrams along the way.

    Campervan Wiring Basics

    From best wire size recommendations to wiring layout advise, our post covers all you need to know about campervan wiring basics. Bonus: Learn about what we did wrong and what we’d do instead if we built a second van!

    Free eBooks To Help You Build Your Campervan's Electrics System

    To see how our van’s electrics system is built, we put together two free eBooks that you can download.

    Each eBook has detailed diagrams with clickable product images so you can quickly purchase and put together your own camper’s electric system.

    Solar Panels For Camper Vans

    (Go Off-Grid With A Proper Solar PV System)

    Complete camper van solar installation wiring guide

    Planning to travel off-grid? Then integrating a robust solar panel system with your camper van electrics to charge your batteries is a must.

    Though we can also charge from shore power and while we drive, power supplied by the sun is, by far, the #1 way we charge our batteries.

    Below, we provide and awesome 7-post series on how to get your solar panel system up and running.

    Learn More About Building A Solar Panel System

    Solar System Beginners Guide

    This ultimate solar guide will teach you everything to build a solar PV system in a van. Included are intuitive wiring diagrams and useful product recommendations.

    How Much Solar Do You Need?

    Not sure how much solar you need to install on your camper van? Check out this post to walk you through the proper way to calculate your ideal solar system size.

    120v AC Power With An Inverter

    (Charge Your Standard Devices With AC Power)

    Inverter Wiring Diagram For Camper Vans & RVs (Complete)
    Fig 4.1 - 120v System Installation

    If you plan to charge laptops, power a blender, or even just use an electric toothbrush, it’s necessary to have a solution to run AC power (120v) in your camper van.

    Yes, if a certain device plugs into a regular house socket that means it runs only on 120v power and you won’t be able to run the device directly from your 12v system. You’ll need an inverter to boost the voltage from 12v to 120v.

    Luckily, installing an inverter in a camper can be as simple or as complicated as you want it to be. Read our post below to learn more.

    Learn More About Building A Solar Panel System

    Install An Inverter In Your Camper

    What are the benefits of an inverter and do you even need a large, bulky inverter? We cover these questions in this post including how to install a full-sized inverter in a camper van.

    Connect To Vehicle Starting Battery

    Camper Van Electrical System - Fig 6.1: Connecting House Batteries To Vehicle Starting Battery

    One of the best and most reliable ways you can charge your camper’s batteries is by driving. When you drive, the engine automatically begins to charge your vehicle’s starting battery. And with the right connection, you can also charge your house batteries while driving.

    Caveat: The method and components we used are intended for those with lithium campervan batteries.

    What You Need

    Product Purpose Where To Buy
    250amp Fuse Protects electrics from surges, Amazon-Button
    Fuse Holder Houses the 250amp fuse. Amazon-Button
    Battery Isolation Manager Regulates the voltage from vehicle battery to camper batteries. Amazon-Button
    1. Vehicle Battery To Fuse

    Locate the positive terminal of your vehicle’s starting battery and run a short piece of 2/0 wire to a 250amp Fuse (and Holder).

    In our case, we tied down the fuse holder to a spot under our van’s hood.

    The purpose of this fuse is to protect the batteries from unexpected electrical surges.

    2. Fuse To Lithium Battery Isolation Manager

    Next, run another short piece of 2/0 wire from the fuse to the “Batt Chassis” post on the lithium battery isolation manager (BIM).

    This isolation manager is the brain of the battery charging process and cycles the charging process on and off to prevent overheating of your vehicle’s alternator.

    3. Connecting To Our Campervan Batteries

    With 2/0 wire, connect the “Batt Coach” binding post of the BIM to the positive bus bar.

    4. Ignition Connection & Grounding

    In order for the battery monitor to know when the ignition is turned on, we hooked a 12awg wire from the BIM post labeled “Ign” to our van’s fuse box under the hood. We found an unused fuse socket that is ONLY activated when the van is turned on and stuck our 12awg into the socket.

    To ground the whole system, take another 12awg wire and connected from the BIM’s “Gnd” post to a ground point on the van’s chassis.

    Final Result (Fig 6.1)

    When finished, the entire connection should look like the diagram below.

    Camper Van Electrical System - Fig 6.1: Connecting House Batteries To Vehicle Starting Battery
    Fig 6.1 - Connection To Vehicle Starting Battery

    Finished! Complete Camper Van Electrical System

    If you followed our campervan electrical system chapters , you would end up with a flexible and robust electrical system that you can rely on no matter the environment you’re in.

    1. Three ways to charge your batteries

    • Solar Panels
    • Shore Power
    • While Driving

    2. Properly placed switches, fuses, & breakers

    All ‘downstream’ components are protected from unexpected electrical surges with the switches, fuses, & breakers we put in.

    3. Birdseye Snapshot of Your Electrical System

    With the bluetooth-enabled Victron Battery Monitor and Solar Charge Control, we are able to understand the status our electrical system day after day. We always know what our battery’s state-of-charge is as well as how much solar energy we harvested that day.

    Final Camper Van Electrical System Diagram

    If you finished building your camper vang electrical system following our steps, your system should look similar to the diagram we put together below.

    Remember, you can always download our Van Electrical Wiring Diagram for FREE.

    Camper Van Electrical System Installation - Complete Electrical System Diagram
    Complete Camper Van Electrical System Diagram

    Tips To Maintain Your Camper Van Electrical System

    Campervan Electrical System Installation - Battery Monitor

    Just because you’ve finished building your camper van’s electrical system doesn’t mean the work is over. While traveling in your van, it’s a good idea to keep up with proper maintenance of your electrical system.

    In our case, maintaining our van’s electrics mainly involves two areas.

    Best Battery Charging Tecniques

    Knowing how to properly charge your batteries is crucial to the long-term health and lifespan of these batteries. Spoiler alert: Different battery chemistries require different charging strategies.

    Did you know:

    • Traditional AGM batteries should not be discharged lower than 40%?
    • Lithium batteries don’t like to be constantly kept at 100% charge?

    Doing either of the above can significantly reduce the lifespans of those batteries. And we’ve seen multiple van lifers throw away almost new batteries simply because they didn’t understand proper battery charging & discharging techniques for their own batteries.

    If you’re interested to learn more on how to maximize your battery’s lifespan and prevent unnecessary, additional battery expenditures, read our battery maintenance article.

    Make Sure Screws & Bolts Are Tight

    Because of all the vibrations that our camper van incurs due to driving, all the screws and bolts in our van electrics become loose over time.

    Of course, we want everything in our van generally being held tight together, but loose electrical components is also a fire hazard. Short circuits in a camper can, and do, happen.

    So once a month, it’s a good idea to take a screw driver and a ratchet and make sure every screw and bolt is fastened tightly.

    FAQ - Camper Van Electrical Systems

    Watts, Amps, & Volts. Do I Really Have To Understand These Electrical Terms?

    Eh, not really. You definitely do not need a degree in electrical engineering to complete your own campervan electrical system. You can simply follow our free  PDF guide and be one your way. But if you’re interested to learn more, knowing basic electrical jargon can help you better understand what’s going on “under the hood”.

    I Have Zero Electrical Experience, Can I Do All This By Myself?

    Yes, you can! We also had zero experience in electrical systems and managed to piece together quite a complicated system that has served us well for over 2 years. Our step-by-step electrical installation instructions can get you from start to finish.

    There Are So Many Different Wire Sizes. Which Do I Need?

    We understand there are ways to calculate the ‘proper’ wire size you need for each type of electrical device you want to run based on that specific device’s power consumption. Frankly, it’s a waste of time.

    We list the only four wire sizes you need for your electrical system.

    • 2/0 AWG To connect the batteries to the bus bars, inverter, and vehicle starting battery.
    • 10 AWG For all solar panel connections.
    • 12 AWG For all 120-volt connections, if any.
    • 14 AWG For all 12-volt devices.

    How To Ground Your Camper Van Electrical System?

    Unlike a regular house, a vehicle doesn’t have normal “ground” points. In the case of campervans, it is OK to ground your electrical devices to the vehicle’s chassis. In our Ford Transit there are multiple “ground” chassis connection points.

    Ford Transit ground points on the chassis

    The above diagram shows all the possible chassis ground points on a Ford Transit van. We primarily used 31 & 35 for our ground points.   

    MPPT Charge Controller vs Cheaper PWM?

    Those converting their campervan’s on a budget tend to purchase PWN Solar Charge Controllers because of their lower price point. But the newer MPPTs are roughly 10-20% more efficient at putting solar energy back into your batteries. To us that’s enough reason to spend a bit more on an MPPT.   

    Should I install a tilt system for my solar panels?

    Being able to tilt solar panels towards the sun can significantly boost your daily intake of solar power, which is especially useful in the winter when the sun has a lower travel arc. We did not install a tilt system and our 350 watts of solar have provided more than enough power in both winter and summer traveling. And in the small occurrences when our batteries do run low, we simply hook up to our van’s vehicle starting battery to charge our batteries while driving.   

    Do you recommend getting an inverter/charger so you can connect to shore power?

    Having the option to connect to shore power is convenient. Though we do not often stay at pricey RV parks with supplied shore power, we do on occasion stay at these parks for 1-2 weeks to rest and recoup. Being on the road 24/7 is draining! And we’ve found that many RV sites are quite shaded, which is nice, but is terrible for harvesting solar power. In the shade, our batteries will reach 0% in 4-5 days. So being able to connect to shore power has given us more flexibility.

    I’m building my camper van electrical system on a budget. What should I not skimp out on?

    100% don’t try to save money on batteries. They are the life blood of your campervan electrical system. And so much of ‘van life’ depends on electricity. Even if you can’t afford fancy lithium batteries, as best as you can, get good quality AGM batteries. And while battery quality is important, battery QUANTITY is just as crucial. Read our article to figure out what size battery bank you require. Undersizing your battery bank will lead to faster battery degredation and wasting money to purchase new batteries.

    Recommended Tools To Build Your Camper Van Electrical System

    All-In-One Tool

    This tool cuts, strips, and crimps wires of all sizes from 10-16AWG. We used this tool almost every day that we worked on our electrical system.


    We used this invaluable tool to check electrical connections during our installation and keep it with us even while we travel. IMO, it’s indispensible.

    Heat Gun

    We added heat shrink to every wire end to reinforce the wire’s connection to ring, butt, and fork connectors. So this heat gun was used frequently during our electrical installation.

    Hammer Lug Crimper

    Cheap and useful tool to hammer those large copper ring connectors to our thick 2/0 AWG wires.

    14awg Butt Connectors

    Essential little connectors to make connections to all our 12-volt devices all throughout our van.

    Final Thoughts: Building Your Own Camper Van Electrical System is Rewarding!

    We hope you learned enough from our camper van electrical system article to be able to build your own electrical setup.

    When we first started, the whole process was completely overwhelming. There were so many components to purchase and so many steps to complete. But we took our time and made sure each step was done to the best of our abilities.

    In the end we found the entire process of building our own electrical system in our van conversion both completely doable and a highly rewarding process!

    If you have any questions or comments about our van electrics article, please post a comment below or send us an email through our Contact Form.

    Thank you!

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