DIY Camper Van Electrical System – September 2020

DIY Camper Van Electrical System – September 2020

This is my latest electrical system recommendations as of September 2020. I will update this post over time and link to newer versions or other options as necessary.

Disclaimer: this is not electrical advise. Rather, this is an illustration of an example electrical system that we use in our vans and customize as needed. Always do your own research and use this information at your own risk. 

This post includes a detailed wiring diagram and complete list of materials needed to put together a very reliable and robust electrical system for your camper van that is capable of extended off-grid adventures and powering just about anything you throw at it.


  • 300 (or 400) amp hours of lithium battery storage
  • 400 watts of rooftop solar
  • 2400 watt inverter (up to 6000 watts surge) with 120 amp shore power charging capacity
  • Integrated 12 volt DC and 120 volt AC load center
  • 60 amps of alternator charging when driving/engine is running
  • Optional pre-inverter shore power outlets
  • Battery monitoring with Bluetooth

It’s super important to realize that there are hundreds of ways of skinning this cat. How awful. We won’t be skinning cats and neither should you. Anyway, the point is that this information should be considered a guide not gospel. You certainly could build out this system exactly as detailed but I would recommend considering your particular needs and then adjusting accordingly.

Also, wire lengths matter. This electrical diagram assumes that there is about a 20′ run from the vehicle battery back to the driver side wheel well where the “primary” electrical system is installed. What I mean by “primary” is most of the stuff you see on the wiring diagram – all the main parts but not the “branch circuits” that power the actual loads in the van like lights and fans, etc. It also assumes all those components are close together – not more than 5 (ish) feet of cable run between them. If your actual setup is different than this you need to adjust the wire gauge (AWG) accordingly. The Blue Sea Circuit Wizard is a great tool for understanding what gauge wire you need. You put in the load in amps, the length of the cable run and how long it will be running in minutes and it will tell you the correct gauge. I favor “over gauging” in general. Wire is pretty inexpensive relative to the other parts. In this wiring diagram I have also over gauged to keep it a bit more simple so that you don’t need so many types/gauges of wires and lugs and so on.

Most of the components are Victron Energy units that are considered some of the best and that we sell right here from our Vanlife Outfitters store. However, there are some Renogy solar panels and their DC-DC charger and I’m recommending Battleborn Batteries (which we also sell) because after much research, I think they’re the best value.

Why A 50 Amp Breaker?!

With most 2000 or 3000 watt inverters you would match the shore power’s 30 amp inlet on the output side. However, Victron Multiplus inverters have a unique feature -they will actually supplement the utility power coming in from the shore power plug with their inverted power – up to 3000 additional watts. So, if you manage to have enough stuff running in your van to exceed the 30 amp service from the shore power, the inverter would actually fill in the gap instead of tripping the shore power breaker. So, while this is not likely to happen unless you’re running some kind of crazy loads in your rig, it’s important to provide circuit protection and adequate wiring “just in case”. Therefore this wiring diagram calls for a 50 amp breaker downstream from the inverter with 6 AWG wire instead of a more “typical” 30 amp breaker with 10 AWG wire.

Inverter Wattage

If you look closely at the specs of the Victron Multiplus inverters they don’t actually support continuous 2000 or 3000 watts respectively. This isn’t important but it can be a bit confusing because of how they’re named.

The MultiPlus 12/3000/120 outputs 2400 watt continuous output at 77 degrees, 2200 watts at 104 degrees and surge up to 6000 watts.

The MultiPlus 12/2000/80 outputs 1600 watt continuous output at 77 degrees, 1450 watts at 104 degrees and surges up to 4000 watts.

Overwhelmed? You’re not alone! Electrical systems can be extremely confusing. That’s why I’ve gone into so much detail in this post. I’ve worked with many DIY van builders who, understandably, can’t wrap their head around their electrical system. However, most of the time, once they purchase all the components and start to lay it out it starts to come together for them. So, I recommend you do the same. Get all the materials, decide where you’re going to install your system and measure that area. Then tape out a section of a table or counter top and start putting the various components together into that space. This will help you get an idea of where each device should be located and everything will likely start to make more sense. Then you can use either tape or string to start “virtually” hooking things up. Some people use various colors of electrical tape to represent various wire gauges. Going through this exercise will help you plan your install and understand how everything works together!

We offer also offer hourly consulting if you’d like us to review your specific electrical plan or offer guidance. Contact Zach for more information or to get something scheduled!

A Little Battery Update (December 2020)
In addition to the complexity, the other pain point around electrical systems is how expensive they are. In particular, the leading brands of lithium batteries (like Battleborn) are crazy expensive – about $1,000 per 100 amp hours. It’s a classic sort of “pay for what you get” scenario and there are good reasons to purchase the highest quality components. For example, the are excellent quality, designed to last for many years with 10 year (!) warranties. But, the truth is that not every van build needs the very best batteries and there are well-made alternatives that are just about half the price! In some cases, having more capacity (amp hours of stored energy) may be better than more longevity. You can ask yourself, do I want to run the stuff in my van twice as long for a few years or half as long for a decade?

Anyway, Will Prowse made an excellent video testing out well-built but lower cost lithium batteries that is worth checking out. One example is the SOK 206 amp hour battery that is currently selling on Amazon for $1,029.

Wiring Diagram

The image below is for quick reference but I recommending downloading the PDF file (below) for much more detail and the ability to print/zoom in.

Item Cost Quantity Total Notes
Battery Bank
Battleborn 100 amp hour lithium battery $949.00 3 $2,847.00 (I would recommend a minimum of 3x for most rigs but you can also add 4x to this system)
After extensive research and lots of vanlifer feedback I think Battleborn lithium batteries are the best value out there. However/good enough. Victron Lithium batteries would seem logical in a mostly-Victron system but, in my opinion, they are not as good of value and require separate battery management systems and other components to use effectively. …. All that said, not everyone needs the very best batteries. See my “battery update” above. If you’re on a budget or not going to be traveling in your van for a super long time, you might consider something like the SOK 206 amp hour battery that is about half the price of a Battleborn.
Blue Sea 300 amp battery switch $28.00 1 $28.00 This will serve as the main disconnect between your battery bank and all the DC loads so you can turn the system off when needed. You want the one that is labeled “on, off w/ knob”.
Blue sea ANL fuse holder $43.00 1 $43.00 This will hold the fuse that protects the wiring between your battery bank and the Lynx distributor.
Blue Sea 400 amp ANL fuse $30.00 1 $30.00 This fuse will go into the fuse holder (above). You should consider having a spare!
Victron Energy battery monitor with Bluetooth BMV-702 $205.00 1 $205.00 The BMV-712 allows you to monitor all the energy (current) being consumed by things in the van or energy (current) being generated from solar or other charging methods. You can see this in both amps or watts and also monitor the the voltage of your battery bank. In addition, the unit also has a sophisticated algorithm to display the state of charge of your battery bank in both percentage of capacity remaining and remaining amp hours. Using the Bluetooth connectivity and the Victron app, the you can log historical data including energy use, battery efficiency, deepest discharge, number of charge cycles and more.
Victron Energy MultiPlus 3000 watt inverter/charger with remote control $1,425.00 1 $1,425.00 The inverter will either pass through utility (shore) power when available or “invert” your battery bank’s 12 volt DC power to 120 volt AC power which is what you’re used to in a home for things that need that type of power such as electronics, water heaters, microwaves, etc. It also has a “charging” function that will take utility (shore) power and charge your battery bank with that energy – up to 120 amps. 2400 watt continuous output at 77 degrees, 2200 watts at 104 degrees, surge up to 6000 watts
350 amp mega fuse $11.00 1 $11.00 This fuse will connect across the 1st position on the Lynx controller for circuit protection between the positive bus and the inverter DC input
Alternator Charging – DC-DC Charger
Renogy 60 amp DC-DC charger $258.00 1 $259.00 Once again, I divert away from a 100% Victron system. Victron’s equivalent DC-DC charger only outputs 30 amps for about the same price (Orion Smart 30 – It does have Bluetooth capability for setup but the Renogy product works well and is double the output. The down side is that you must run a “trigger wire” from the van ignition switch so that it knows when to turn on and start charging. More on that below. The Victron unit can sense voltage to automatically trigger itself to turn on. It is also possible to use 2x of the Victron units in parallel to equal the same output but it’s more wiring, twice the price and also requires the “trigger” wire that the Renogy unit does.
Connector (male) for using the “upfitter connector” as the ignition “trigger” for the DC-DC charger $1.00 1 $1.00 Please see the “Trigger Wire for Renogy DC-DC Charger” section for more details.
Pin for “upfitter connection” $0.50 1 $0.50 Please see the “Trigger Wire for DC-DC Charger” section for more details. You only need one of these but they are super cheap so I would recommend getting at least a few to practice with.
Distribution/Load Centers
WFCO WF-8930/50NPB-50 50 amp (or 30 amp) AD/DC load center $89.00 1 $89.00 Accommodates up to 12x AC circuits and 15 DC circuits
Square D 50 amp HOM type single pole circuit breaker $12.00 1 $12.00 Main breaker for AC distribution.
Square D 15 amp HOM type single pole circuit breaker $5.00 3 $15.00 You’ll want one of these for each 120 volt AC branch circuits. I’ve indicated 3x here but you may need more.
Victron Energy Lynx Distributor (DC) $205.00 1 $205.00 This product is pretty neato. It really cleans up your wiring since it serves as a 1) positive bus bar 2) negative bus bar and 3) 4x fuse holders. So, it combines a lot of things into one box that you would normally need additional wiring and components for. And, if you consider not needing to purchase all those things, it’s a great value too.

Note about LED lights: often this Lynx Distributor is paired up with the Lynx Shunt or a Victron BMS. But, those are not needed if you use the BMV-712 battery monitor I’ve listed here that has its own shunt for monitoring. Those devices are what normally powers the Lynx Distributor’s fancy LED lights that indicate if each of the circuits are working (fuse not blown). However there is a way to do this (hack?) without the devices which I detail toward the bottom of this post. Click here to jump down to that section.

80 amp mega fuse $8.00 4 $32.00 1x fuse will connect across the 2nd position on the Lynx controller for circuit protection between the positive bus and the load center DC input.

1x fuse will connect across the 3rd position on the Lynx controller for circuit protection between the solar controller output and this positive bus on the Lynx.

1x fuse will connect across the 4th position on the Lynx controller for circuit protection between the DC-DC battery charger output and the positive bus.

1x fuse goes between the vehicle battery positive terminal and the positive cable run from the vehicle battery to the DC-DC charger DC input.

Solar System
Renogy 200 watt (12 volt) monocrystalline solar panel $300.00 2 $600.00 These are quite wide (24.1V, 63.8 x 25.9 x 1.4 inches). You may decide you prefer a smaller panel with slightly reduced output if they don’t fit up on your rig’s roof. Since I like to have air conditioning and vent fans/etc. up on my van roof, I wanted a total of 2x panels but if you have more space, there are certainly more options!
Weatherproof solar cables entry gland $12.00 1 $12.00 After you drill a hole in our roof, this can cover that up and the cables from your solar panels can go through this down into the van. There are two entry glands – one for your positive and the other for the negative.
Victron Energy SmartSolar MPPT 50 amp charge controller 100/50 $228.00 1 $228.00 The charge controller takes the raw power from your solar panels (around 48 volts and 9 amps in this case) and converts it to the correct charging voltage and current for 3-stage charging of your battery bank.
2-pole, solar disconnect switch (16 amp) $17.00 1 $17.00 This breaker/disconnect is wired between the solar panel wire coming down from the roof and the solar panel (PV) input on your charge controller. This allows you to disconnect both the positive and negative current flow and essentially “turn off” your solar panel’s output.
12″ length of DIN railing $6.00 1 $6.00 This DIN railing is what you cut to size for the solar disconnect switch listed above. The rail mounts wherever you want the switch located and then the switch snaps into the rail. Alternatively, if you want this installed into a tidy box, you could use something like this that includes the DIN rail.
Renogy solar panel mounting brackets (2 sets of 2x) $20.00 1 $20.00 These “z-brackets” will mount your solar panels to your roof. I recommend using plus nuts and then covering the entire bracket with Dicor sealant.
Shore Power
30 amp shore power inlet $18.00 1 $18.00 This is normally installed on the outside of the van on one of the side walls. Some people prefer to hide it more by installing onto a box below the bumper. The white plastic on this inlet tends to yellow in the sun quickly so I recommend you paint it white (or whatever color) with a high quality spray paint before installing. I considered some of the more expensive models but that really is the only down side to this one that I’ve found and it’s quick to paint.
25′, 30 amp shore power cable $55.00 1 $55.00 Used to hook up to shore power from a campground/home 30 amp plug.
15 amp to 30 amp adapter $10.00 1 $10.00 You can use this adapter to use your shore power cable with a standard, 15 amp outlet.
Optional For Pre-Inverter Shore Power Outlet(s)
If you want to have one or more outlets connected to utility (shore) power that work when the shore power is present and the inverter is turned off, you can add this optional breaker box and outlet. You can add additional outlets to this circuit if necessary. One reason to do this, in my case at least, is to power the refrigerator off shore power whenever available. Since my refrigerator “defaults” to running the compressor from 120 volt AC vs. the 12 volt DC connection, if I were to plug the inverter into one of my normal (downstream from the inverter) outlets, the refrigerator would run of AC power any time the inverter was turned on which is less efficient than running from the direct, DC power. Therefore, I have this “pre-inverter” shore power that the refrigerator is connected to so that it only runs off AC power when there is utility (shore) power.
Square D 30 amp, 2-space circuit breaker box $15.00 1 $15.00 This breaker box is connected between the shore power inlet and the inverter to provide 1) additional circuit protection if the shore power source is misconfigured and 2) the ability to wire up a pre-inverter outlet/circuit. See above.
Square D, 30 amp QO type single pole circuit breaker $8.00 1 $8.00 This becomes the “main” breaker for the pre-inverter 120 volt AC wiring.
Square D, 15 amp QO type single pole circuit breaker $8.00 1 $8.00 This circuit breaker is wired into the load side of the main 30 amp breaker (above) to create a 15 amp circuit for the pre-inverter outlet(s).
3/8 in. twin-Sscrew cable clamp connectors (5-pack) $5.00 1 $5.00 You’ll use 3x of these: one for the shore power wire that comes into the breaker box, a second for the wire going out to the inverter inlet and the third for he wire going out to the pre-inverter outlet(s).
6-outlet power strip $10.00 1 $10.00 You’ll cut the male end off this and then wire it directly to the 15 amp circuit breaker to have a few “pre-inverter” outlets.
Wire + Lugs + Heat Shrink + Connectors
10′ red and black (20′ total) 4/0 AWG cable $90.00 1 $90.00 This heavy duty cable will be used to connect your battery bank to the Lynx DC distributor (through a main cut-off switch on the positive side). It will also be used to connect the between the Lynx Distributor to the inverter. This allows for up to 5 feet of cable for each of these runs on both the positive and negative side.
20′ red 2 AWG cable $38.00 1 $38.00 Cable run from vehicle battery to DC-DC charger (positive).
20′ black 2 AWG cable $38.00 1 $38.00  Cable run from vehicle battery to DC-DC charger (negative).
15′ red 6 AWG cable $20.00 1 $20.00 Used for the following DC positive runs:
Approximately 5′ – used between the output of the solar charge controller and the positive bus (Lynx controller).
Approximately 5′ – used between the output of the DC-DC charger and the positive bus (Lynx controller).
Approximately 5′ – used between the positive bus (Lynx controller) and the DC input on the load center.
10′, red and black 10 AWG solar extension wires with one male and one female MC4 connectors $19.00 1 $19.00 These cables will be used to connect your solar panels down through the entry gland to your solar charge controller. They come with the “matching” MC4 connectors you’ll need up on the roof and bare wire on the other side where they will connect to the solar disconnect switch. Then you’ll need a little bit more 10 AWG to go between the output of that disconnect switch to the PV inputs on the solar controller itself.
10/3 stranded copper cable (3x 10 AWG wires inside an insulated jacket) $2.00 10 $20.00 This cable will be used to connect the shore power inlet to the pre-inverter load center (if used) and from the load side of the main 30 amp breaker in this panel to the inverter input power connections. If you don’t use the pre-inverter load center you won’t need as much cable and it will go directly from the shore power inlet to the inverter input power connections.
6/3 cable (3x 6 AWG wires inside an insulated jacket) $78.00 10 $780.00 From the inverter’s output to the AC/DC load center’s AC main breaker. This carries the 120 volt AC power from the inverter (and via shore power through the inverter) to your load center and all the downstream AC circuits.
25′ of black and red 16 AWG cable $8.00 1 $8.00 I would recommend using the red wire for the ignition trigger wire from the “upfitter connection” on the passenger side “b-pillar” back to the location of the DC-DC charger. Whatever remains can be used in various places on your build including low draw DC circuits such as lights, etc.
10-pack, 4/0 AWG 5/16″ lugs $21.00 1 $21.00 These lugs will be crimped onto the 4/0 AWG wire used between the battery bank and the Lynx distributor and to the inverter.
10-pack, 4/0 AWG 3/8″ lugs $21.00 1 $21.00 These lugs will be crimped onto the 4/0 AWG wire used in places where you need the larger 3/8″ lug.
25-pack, 4 AWG 5/16″ lugs $15.00 1 $15.00 These lugs will be crimped onto the 6 AWG wire used throughout the system.You’ll need about 12 but extras are helpful!
15-pack, 2/0 AWG 5/16″ lugs $22.00 1 $22.00 These lugs will be crimped onto the 2/0 AWG wire that connects each battery together. You’ll have a few extra which is handy.
25-pack, 6 AWG 5/16″ lugs $15.00 1 $15.00 These lugs will be crimped onto the 6 AWG wire used throughout the system. You’ll need about 12 but extras are helpful!
10-pack, 2 AWG 5/16″ lugs $13.00 1 $13.00 These lugs will be crimped onto the 2 AWG wire used for the connection between the vehicle battery and the DC-DC charger.
Black 3/4″ heat shrink (4′ length) $8.00 1 $8.00 Heat shrink for 2/0 AWG cables and 2 AWG cables
Red, 3/4″ heat shrink (4′ length) $8.00 1 $8.00 Heat shrink for 2/0 AWG cables and 2 AWG cables
Black 1/2″ heat shrink (4′ length) $6.00 1 $6.00 Heat shrink for 6 AWG cables
Red 1/2″ heat shrink (4′ length) $1.00 1 $1.00 Heat shrink for 6 AWG cables
Various heat-shrink, crimp-on spade connectors $22.00 1 $22.00 The positive wires for 12 volt DC branch circuits to things like lighting/refrigerator/etc. will connect to the load center using these spade connectors. This kit includes common sizes for wires you’ll likely use for this.
Various blade fuses $9.00 1 $9.00 This variety kit of blade fuses is a simple way to have a range of capacity for fuses you’ll need for the 12 volt DC load center branch circuits.
1/4″ thick x 1″ tall x 6″ long copper flat bar $18.00 1 $18.00 You’ll cut short sections of this flat bar to use instead of a wire. In some cases, where your connections are very close together – such as the connection between the 300 amp battery switch and the Lynx distributor, it’s easier and cleaner to use straight copper. 1/4″ thick by 1″ tall flat bar is roughly the same conductive equivalent as 4/0 wire which you could use instead of this. Once you cut the copper bar to length you can drill appropriately sized holes and use 5/16″ bolts with washers and nuts to tighten down the connections.
System Total $6,709.50

Note: pricing is as of September 2020 and will change often. However, I wanted to provide some context around the cost of a system like this.

Trigger Wire for Renogy DC-DC Charger

Unlike some other battery-to-battery charging products that sense voltage and trigger the charging based on that, the Renogy DC to DC charger (or battery-to-battery charger) that I used requires you to connect up a 12 volt positive “signal wire” from the vehicle’s ignition switch so that it only charges from the van (vehicle) battery when the ignition is turned on. Without this ignition trigger on this unit or the voltage sensing on others, the battery-to-battery charger could easily drain the van battery since the battery-to-battery charger would be pulling current without the alternator providing a charge.

After some research I discovered that Promaster vans have a “Upfitter Connector” on the passenger side “pillar” which is that area just behind the passenger seat where the seat belt connects to the van wall. If you remove the black plastic trim at the bottom of this “pillar” you’ll see a white multi-pin connector (photo below). This is the “upfitter connection” that provides a variety of connection points for the Promaster in one spot. This PDF file (Promaster Upfitter Connector Diagram PDF) details this connector including what each pin on the connector is/does. Turns out that pin #13 is an “ignition feed” that has 12 volt positive when the ignition switch is on. So, I used this to be the “trigger” for the Renogy DC to DC charger.

Close Up Shot of Promaster Van Upfitter Connector with Pin #13 Connected:
Promaster Van Upfitter Connection

In order to do this, I had to order the correct, “male” version of this connector as well as the “pin” itself. The way this works is that you solder the correct wire to an empty pin and then insert that pin into the correct position on the connector thus allowing you to access and wire up a variety of things to this upfitter connector. These parts are pretty inexpensive so I bought a few with the expectation that I’d destroy a few figuring out how this all works. I’m glad I did because I did indeed destroy a few experimenting. Ultimately, it’s not difficult but finding the right parts and how they fit together took some time. So hopefully this saves you that time!

Soldering the Wire to the Pin:

The wire coming out of pin #13 on the Upfitter Connector runs back to the rear passenger side wheel well where the primary electrical system is installed and is connected to the Renogy DC to DC charger on a terminal labeled “D+”. Below is a photo of this connection:

Next I had to configure the Renogy DC to DC charger to correctly charge the lithium batteries using the DIP switches pictured above. The manual for this Renogy DC to DC charger is really bad and the section on setting up the DIP switches is complete gibberish. I gave up on it pretty quickly and called into Renogy support. The correct DIP switch settings for charging lithium batteries with the Renogy DC to DC charger is:

  • Switch #1: Off
  • Switch #1: On
  • Switch #3: On
  • Switch #4: On
  • Switch #5: Off

Turning On The LED Lights On The Lynx Distributor

There are LED lights on the Lynx Distributor that indicate if each of the circuits is live (the fuse isn’t blown). They light up green when it’s good and red when it’s not. These lights are normally powered when the Lynx Distributor is paired up with the Victron Lynx Shunt but you don’t need that if you use the “better-for-vanlife” (my opinion) BMV-712 battery monitor (listed above) which has it’s own shunt for monitoring.

So, if you don’t want to buy that hardware but do want the fancy lights, you can “hack” the lights with a 12 volt DC to 5 volt DC converter and an RJ11 “phone style” connector. This will provide the 5 volt power the LED lights need to fire up. Below is an illustration on how you’d do this – at your own risk, of course.

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