Our Camper Vans Electrical System with wiring diagram for lithium batteries solar panels and inverter chargers
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Our Camper Van’s DIY Electrical System

A camper van’s electrical system is the life blood of the tiny home.  It comes in all shapes and sizes and is completely customizable based on each individual needs.  In this post, we provide a complete overview of our camper van’s electrical system.

If you’re new here, welcome!  I highly recommend you check out of Van Build Journey page for more information on our entire van build.  

Also, check out of YouTube Channel to see our entire van build series covering over 40+ episodes showcasing every step of the build!

Our Van's Electrical System

Our van consists of four main electrical components.  

  1. Batteries
  2. Solar Panels
  3. Inverter/Charger
  4. Battery Isolation Manager

Now your system doesn’t need to have all four of these components in fact you can get away with just a single battery if you really wanted too.  However, we really wanted to have the feeling of home in our Sprinter Van so we went all out.  

Below are the 4 core components we use in our van today.  

Our DIY Converted Sprinter Van Camper Van Electrical Systeem

1. Batteries

When it comes to batteries, there are a few different types.

  1. Lithium Batteries
  2. AGM Batteries
  3. Lead Acid Batteries
  4. Gel

Unfortunately I do not know much about batteries however I do know for a FACT that Lithium Batteries are usually the best!  But they also come with a higher price tag.

Lithium Batteries let you drain the battery level to well below 50% before damaging the battery, unlike the other battery types.  This makes me feel more confident when using our power. 

So if you wanted a similar battery bank of Lithium Batteries you basically need to double it to match.  For example, a 100 Amp Hour Battery Bank of Lithium Batteries will match 200 Amp hours of AGM, Lead Acid, and Gel Batteries. 

Batteries We Use

In our build, we have 3, 100-Amp Hour Battle Born Batteries.  Like I mentioned above these batteries can be drained beyond 50% without risk of damaging the batteries and they have a built in Battery Management System (BMS).  

From Battle Born’s website: “The BMS protects the cells against excessively high or low voltages, high currents, short circuits, and excessive heat or cold. These are the most common causes of battery failures, and we have taken every precaution to mitigate these risks in all of our batteries.”

This let’s me sleep at night knowing that the BMS is protecting us at all times!

With a 300Amp Hour Lithium Battery Bank we have plenty of power our van like a tiny home, meaning we can have running water, power a hot water heater, charge all our accessories, power lights, and even power household items like a blender and a hair dryer!  

If you think you’re going to live in the van full time we highly recommend at least a 300Amp hour battery bank of lithium batteries if it’s in budget, especially if you want to make your van feel like home without making too many electrical sacrifices.   

 

2. Solar Panels

Solar panels are an essential component of your electrical system in any diy converted van.  They help charge your batteries and keep your batteries full of energy.  Once solar is installed, you are able to charge your batteries for FREE directly from the sun.  It’s a pretty cool feeling knowing you’re using natural sources to power your house.  

Solar panels come in different shapes and sizes and with every solar panel install, you will need 5 main things.

  1. Solar Panels
  2. Solar Charge Controller
  3. Wires 
  4. MC4 Connectors
  5. Entry Gland from the Ceiling of your van
 
If you’re new to the world of solar, I recommend getting a Solar Kit from Renogy.  We got the 400 Monocrystalline premium solar kit and were not disappointed. 

Types of Solar Panels

There are two different types of panels, Monocrystalline solar panels and Polycrystalline solar panels.  Monocrystalline panels are more efficient and more reliable but are also more expensive.  We recommend monocrystalline panels due to their reliability and ability to charge your batteries faster.  
 
There are also two different shapes of panels, rigid framed and flexible panels.  Rigid framed are usually bolted down to a roof rack or something similar while flexible panels are usually glued down to a roof.  We went with rigid frame panels since we are traveling at high speeds and I want to have confidence in my system knowing my panels are tightly bolted down, not going anywhere! 
 
There are two different types of panels, Monocrystalline solar panels and Polycrystalline solar panels.  Monocrystalline panels are more efficient and more reliable but are also more expensive.  We recommend monocrystalline panels due to their reliability and ability to charge your batteries faster.  
 
There are also two different shapes of panels, rigid framed and flexible panels.  Rigid framed are usually bolted down to a roof rack or something similar while flexible panels are usually glued down to a roof.  We went with rigid frame panels since we are traveling at high speeds and I want to have confidence in my system knowing my panels are tightly bolted down, not going anywhere! 
 
Installing a custom solar roof rack on our diy sprinter van which includes 4 - 100 watt solar panels of Renogy mono-crystalline panels

Solar Charge Controllers

Solar charge controllers is the component that converts the energy from the sun into a language that your battery can ingest.  Basically, it’s the middle layer between the panels and the batteries that help channel it’s energy into a useable manner.  Typically when searching for solar charge controllers you want to look for something that is compatible with your battery bank system, whether it’s 12v or 24v and what is the maximum amperage.  

 

We use a 40Amp Rover Charge Controller by Renogy, which is rated up to 520 Watts of solar so we have room to expand and add another solar panel if we ever wanted too. 

If you’re chose a setup different from the premium solar kit, than I’d recommend going with a Victron MPPT charge controller.

Wires & MC4 Connectors

Refer to my wiring diagram, for what we used.  If you choose to use the premium solar kit by Renogy the wires and 40amp ANL fuse is included.  Just note if you wire your solar panels in parallel rather than series you may have to increase the gauge of wire to carry the higher amperage over a specific distance.  

In order to connect your panels together you should use MC4 connectors which are water proof and able to withstand external weather conditions.  If you are wiring your panels in parallel, then you will need to get MC4 adaptors for parallel connections. 

Our set up is wired in series rather than parallel.  This allows us to keep the amperage low while adding more voltage that’s still well within the charge controllers limits with an end result of thinner wires.   

The only downside to wiring your panels in series is when your panels are in the shade.  If one panel is in the shade it will effect your entire solar system and reduce the amount of energy sent to your batteries.  In parallel you do not have to worry if one panel is shaded as it would not affect the other panels you have.  

Solar Roof Rack

We built our solar roof rack out of 80/20 aluminum.  I was much more comfortable attaching my solar to a roof rack rather than the van ceiling and drilling more holes directly into the van but to each their own.  

DIY Custom Solar Roof Rack for DIY Camper Van made out of 80/20

Solar Wiring Roof Entry Gland

Hopefully this is obvious but I wanted to call it out.  You need a water tight compartment where you can allow your solar wires to enter the roof of your vehicle into your vehicle’s electrical compartment.  We do this via an entry gland and use a mix of 3M tape and dicor lap sealant to ensure no water can enter the vehicle. 
 

3. Inverter / Charger

If you have any intentions of having house AC (Alternate Current) outlets also known as your regular house outlets than you will need an inverter.  An inverter does what it’s named, inverts DC energy into AC energy and if it has a charging component built in, then it inverts AC energy into DC to charge your batteries.  

There are several different options when it comes to Inverters, and most van lifers use a 2000 Watt or 3000 Watt Inverter.  The more watts you have the more energy you can handle.  We have a Bosch 2.5 Gallon Hot Water Heater which has a pretty big draw and uses a lot of watts.  Due to this we need a 3000 Watt inverter to power it and a 3000 Watt inverter requires at least 3 – 100Amp Hour Lithium Batteries.  

 

 

The Inverter/Charger We Use

Like I just mentioned above, we use a 3000 Watt Inverter from Victron, it’s the Victron Multiplus 12/3000/120-50 120V.  This model is a BEAST and it’s also a dual purpose inverter AND charger.  This allows us to charge our van via shore power if we ever need too.  However since we have a battery isolator and charge our batteries via the engine’s alternator, we never had to use shore power.  But this is a great option if you want to use a heavy constant load like a hair dryer or additional heater or something similar.   

 

4. Lithium BIM 225 (Battery Isolation Manager)

In my opinion, having a source of charging from your vehicle’s engine is an absolute must.  It eliminates the worry of running out of battery power in any van conversion because you have the on demand power once you start your vehicle.  Now don’t get me wrong, solar is amazing, but solar is completely dependent on the sun, so if it’s cloudy or if you’re parked in the shade you will not be able to charge your batteries! 

You could also use a DC to DC charger which offers a more consistent charge rate at a lower amperage.  This will charge your batteries at a slower rate, but it is less wear and tear on your vehicle’s alternator.  There’s pros and cons to ecah option (DC to DC charger vs Isolator).  

 

Lithium Battery Isolation Manager How to Wire the Li-Bim 225 for a DIY camper van electrical system
Wired up Lithium Battery Isolation Manager
Lithium Battery Isolation Manager How to Wire the Li-Bim 225 for a DIY camper van electrical system momentary switch
This is my momentary switch connected to the door of the driver seat fuse panel

4. Additional Components

In addition to the four critical components above, you also need the brains and the spine of the system to connect everything together. 

  • DC Fuse Block
  • Bus Bar
  • Battery Monitor 

I’d like to think of the bus bar as the spine of the electrical system.  Without it, you’re unable to easily connect all of your main electrical components together completing your system.  We built a custom DIY bus bar from Nate’s blog Explorist.life which is a great resource for electrical information.  

The brains of the system are generated from the battery monitor which is the visual front end of the electrical “Shunt”.  The shunt is what connects your negative cables coming from your battery bank to the negative bus bar.  As energy passes through the shunt, data is captured and displayed on the battery monitor.  

The next critical component is your fuse panel which connects all of your DC electrical components to your battery bank.  We use 2 – 12 circuit fuse panels by blue systems which allows us to put each individual accessory on it’s own fuse.  Now you don’t necessarily have to do that, I just did it because it gives me more piece of mind and lets me assess an issue faster if something doesn’t work.   

Summary

Throughout our entire van build, the electrical system was no doubt my favorite part of the build.  I learned a lot throughout the build and I didn’t have any knowledge about DC electrical prior this.  To keep things short, as you can see from the blog post above, we have 3 sources of power in our van, Solar, Shore Power, and charging via the vehicles Alternator using a Lithium BIM.  I think it’s critical to have both solar and a charging mechanism via the vehicles alternator if you rarely plan to stay at RV campgrounds like us.  We have yet to require any hookup what so ever which makes life really convenient.  

If you have any questions about our electrical system drop a comment below I can continue to update this as questions arise.  Also, please check out our YouTube channel if you’re interested.  We have over 40 episodes related to our build and now share our van life adventures with you! 

One Comment

  1. Nouhad Zantout

    Hi Kevin, your videos are really an inspiration to upgrade an RV.
    you spoke about the electro diagram which is missing on your website, or did I miss something!
    I´m in Germany and trying to find similar products of what you have used, for instance the brass bars` connectors, did you bought them or you had done them yourself?
    your help would be appreciated.
    Thank you in advance
    Nouhad

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