Electrical System

Disclaimer: I am not a professional electrician, this is an example of what we have implemented in our van.

Our van electrical system is powered by two 200ah AGM Deep Cycle Batteries. The batteries are recharged in two different ways. One method is by the two 100W solar panels that are mounted to the roof of our van. The second is the Voltage Sensor Relay that brings charge through the van’s alternator.

The diagram on the right shows how our setup all connects together. We used a combination of 14G, 4G, and 2G wires to complete the setup. 

The electrical system can be broken down into 3 main parts: 

  1. DC loads
  2. AC loads
  3. Charging

DC vs AC... What's the difference?

In the words of a non-electrician, a DC loads are the red and black wires that get wired directly from the device to the fuse box, and the AC loads get plugged into an outlet. The AC loads get their power by wiring outlets directly to the Inverter. 

Our AC loads: 

  • Phone charger
  • Computer charger
  • Anything that requires a 3-prong outlet 

Charging the Batteries

Solar Panels: 

We have 2, 100W Monocrystalline Rich Solar Panels. After doing a significant amount of research, this is a bit on the lower end for solar power. We originally had planned for 300-400 watts of power, but our roof set up did not have enough space. With the combination of our Voltage Sensor Relay (VSR), we get enough charge to keep our batteries above 50%. 


In order for the batteries to receive charge from the solar panels, they need to be wired to a solar charge controller. We went with the Victron Energy SmartSolar Charge Controller. After a good deal of research, we determined that the solar panels should be wired in series, vs parallel, due to the charge controller that we picked. 


Voltage Sensor Relay: 

We have the Marinco Voltage Sensitive Relay. The relay sends charge from our van battery to our 2 batteries every time the van’s alternator turns on. We like this sensor because it is automatic in turning on and shutting off. As soon as the van is turned on, the light turns red and the charging begins. We don’t have to worry about the possibility of forgetting to turn it off and then having our van battery drained.

This was one of the more difficult devices to wire correctly. I had the positive lines connected but was having trouble getting the charge to switch over when the van turned on. Turns out the problem was with my terminal connectors. I had put 2G connectors on 4G wire, and the wires weren’t getting a strong enough connection. Once I redid all of the connections *properly* the system worked!

We really like having this as an option for our batteries to charge. Knowing that we can take the van for a short drive and we’ll be charged up gives us peace of mind on cloudy days!

Our System

This is our electrical system under the bed in the garage. The batteries are located under the lid.

electrical supplies we used


14G red wire – DC connections

14G black wire – DC connections

4G red/black wire – larger connections

2G red/black wire – batteries to bus bar

Split loom tubing – to insulate wires


Fuse Block #1 – DC connections wired here 

Fuse Block #2 – DC connections wired here

Terminal Mount Fuse Block – for positive of the main battery

40 amp fuse – for the solar charge controller 

100 amp circuit breaker – for the VSR

100 amp fuse – for the inverter

Blade fuses – for fuse blocks


14G connectors – for light switches and fuse block

14G connectors – fore wire to wire connecting

4G 5/16 copper lugs – 5/16 fit most of our connections

Extra copper lugs – for the ones that needed something other than 5/16


We have 2 VMAX 12V 200ah AGM batteries. 

Renology Inverter – ours is 1000W. 1500W or higher is better if you plan to use bigger appliances (blenders, griddles, ect). 


Propane solenoid switch – lights up when on

Light switches for LEDs – regular rocker switches


Wire stripping tool  – very helpful

Heat gun  – for any heat shrink connections

Lug crimping tool – for the 4G and 2G copper connections



Bus Bar – we have 2 of these, one for positive, one for negative 

On/Off switch – this controls the entire system

Victron Battery Monitor – helps us see what % the system is always at. Runs off an app on our phones. 

Voltage Sensor Relay – battery to battery charger 

DISCLOSURE: This post may contain affiliate links, meaning when you click the links and make a purchase, we receive a commission.