NOTE: we are not electricians, nor do we hold any certifications in automobile or RV wiring. Prior to this project we had no 12v DC experience outside of wiring in car speakers and the odd accessory. What you see here is how we wired our boogie van, it may not be the right way, even though it seems to work for us. The information here is provided for information only, please consult with qualified automotive or RV service personnel for assistance with your project.
Once we settled on solar with a battery array what remained was how to make the power from solar to the batteries and from there to the things we wanted to charge. We knew that refrigeration would be needed, interior lights, and a means of charging electronics. Given the final interior setup would allow us to cook inside the boogie van we also believed a powered roof vent was required, and we anticipated the future need for 120v so a power inverter was planned. The solar installation is mentioned here, therefore this discussion will begin after the solar panel was in place and the wires attached to the solar panel. The explanation is in no particular order; we did not document the entire process in pictures.
What is described below is commonly called “house power”, as opposed to “vehicle power” or “shore power”. Our house power is not connected to the vehicle’s power system in any way, nor is it connected to shore power. It is a stand-alone power system isolated from any other source of electricity.
Our boogie van has 4 sets of interior roof lights from the front dome lights for the driver and passenger to the cargo lights in the very rear. We lost all our roof lights with a wire-short in our first season, so getting this functionality back was a priority. In our part of the world there is plenty of light at the height of summer, but you get less of it in spring and fall. Roof lights just make sense to sort yourself out after dark and to provide sufficient lighting to cook by. Headlamps work, roof lights work better.
Each light fixture has a separate light and switch for either side of the van meaning there are 8 separate light bulbs available. Standard light bulbs use about 5amps of power each, meaning if all the lights were on we would be consuming 40ah of power. LEDs on the other hand are about 1.5amps each, which by contrast would be 12ah for full lights. We switched all the interior lights out to LED, although in practice we rarely use more than a couple at a time. Best practice is to use low-power consumption items at every opportunity.
The fixtures themselves had a single positive and negative wire running to them. The roof panels were loosened, the positive and negative wires determined, the wiring to each fixture cut and new wires run back along the side of the boogie van to the location of the wiring box. The wires were hidden behind the roof trim. To make later parts of the installation easier, black wire was used for the negative run and red wire for the positive run. I wrapped the ends of the original vehicle wire in electrical tape and left them in place.
Refrigeration and Electronics.
The powered cooler we started off with had a typical round 12v male plug, which we initially plugged into a 12v round female receptacle that ran off vehicle power. The cooler ran at 4.5 – 5amps. When we decided to put in house power, we knew that 12v round fittings would be the most likely way to connect our refrigeration and electronics, even if we needed to buy adapters to attach USB charging. The refrigerator we eventually bought runs at no more than 3amps.
The house power box was to be located behind the driver’s seat which is where a round 12v vehicle power fitting was located. We elected to keep this fitting in place and route it inside our house power box in the event we required it for any reason. There were other such vehicle power receptacles in the boogie van and we have kept them all; they come in handy.
The receptacle for the refrigerator is located inside the power box, the one for electronics exits the power box onto the kitchen counter.
Roof Vent Fan.
We purchased a standard roof vent with a 12v fan at the local RV store. Our boogie van did not have an existing hole for this so I opened up the roof panels so I could see where the wiring and body supports were; I did not want to cut wires or supports. I used a hole template to mark the spot the fan was going to go (just in front of the solar panel, roughly between the two front seats), drilled a starter hole in the roof metal, then cut out the template square using a reciprocating saw. The saw was incredibly quick and efficient for this task.
What you will need to ensure is that you have enough of the putty tape to seal your vent. Our Chevy had roof ridges that complicated this task as the fan does not sit flat to the roof all the way around its opening. While we initially used plumbers putty to fill in the gaps, this eventually leaked and it required re-sealing with silicone caulking.
At some point we envisioned longer road trips and a greater need for 120v power. A long weekend in the mountains is not the same trip as a multi-week drive across the continent, at some point on a long trip you may want to tidy up and do your hair. Even on short trips, small appliances like a bullet-blender come in handy. We did not size our battery array for large appliances, nor does it carry sufficient power even at the height of the day to run major cooking appliances. We sized our inverter for an 1800w maximum load (travel blow dryer) which meant we needed to be able to sustain over 2000w of AC power. We settled on a 2300w inverter to give us the extra wattage required for this task. To simplify using the inverter we attached a small power bar to it so we did not have to enter the power box to plug in.
Wiring the Batteries.
We have 2x 6v batteries at 260ah each. To get 12v we wired them in series (positive to negative) which doubles the volts but gives the same amps. As mentioned in the post on solar power this gives us 12v at 260ah. We looked at 12v batteries but 6v batteries out perform 12v in storage capacity. We bought as much storage as we could afford, and as would fit in the space we had. Each battery was 11x11x7, and about 80lbs each, which was all the size we could take in our power box.
The batteries are connected positive-to-negative at one end which makes the voltage double to 12v. All input and output of actual electricity must occur a the opposite ends from connection this meaning you will have a positive connection from one battery and a negative from the other. You cannot pull 12v from the same end you make the series connection.
Wiring the Solar.
The solar connections were straight forward as the solar control unit was well-labelled with where to put solar in, voltage out to the batteries, and voltage out to the load block. I used the 10 gauge wire that came with the solar kit to wire directly to the controller, the fuse block, the grounding block and the battery array. There was a separate port for the solar remote to connect to. The solar remote is mounted on the outside of the power box and we use it to monitor the state of our house power system. It is quick and intuitive to use for this purpose.
Fuses and Breakers.
All major positive power connections have a circuit breaker in their wiring run. It appeared to me that this would be quicker to disconnect power with than pulling a fuse, and it would allow for easy isolation of any portion of the house power system; it also made the wiring easier than fuses. Each electrical load (light, fan, etc) is connected to a central fuse panel that allows for each to be fused individually as required. There is not a breaker in the line running to the fuse block. All negative wires are run to a grounding block, which seems far tidier and safer than taping the lot together with electrical tape. I bought all the circuit breakers off Amazon, the grounding block and fuse block were acquired from my local RV store. Ensure you get the right sized breaker for your load.
When pulling wires from any location to the power box always leave a few feet more wire than you think you will need to make your final connections. This allows you to change your mind on final connection locations without the need to re-pull any wire runs. This goes for the heavier solar wiring that comes with your kit as it does for the smaller wires. Each run pair of black and red wires (black negative, red positive) should be taped together and labeled so you know what you are hooking up. This matters when you are selecting fuse capacities. Without getting into any deep discussions on what is required for either wire size or fuses, you need to ensure your wires will take the amps of your load, and that your fuses are selected in accordance with the manufacturer’s requirements for the item’s load. For instance, we used 16 gauge wire for our roof lights and 5amp fuses. Too large a fuse capacity may allow for the circuit to overload and cause a fire, too small a fuse capacity may blow your fuses under normal load. Again, always consult with the manufacturer’s recommendations for your electrical devices and with qualified automotive or RV service personnel for your installation.
The Wiring Box.
Below is the finished wiring box for our house power. Where possible wire was secured by taping in bundles and then fixing the bundles with zap straps and wire holders to the power box. The constant moving of the vehicle puts stress on the wires which can be minimized. Tidy wiring also reduces the chance of ripping them out by accident when you are in the wiring box to change a fuse or some other reason.
The lid of the power box is hinged and it has a door on the front to allow for easy access and battery removal. The size of the items, and their weight, fills the box almost to capacity.
A few items to consider when installing house power:
1. Have all the items purchased and handy so you know how big the box needs to be and how the wiring needs to be laid out.
2. Buy or retrofit your house power with the lowest power use items (LED lights, efficient appliances).
3. Use red and black wire to keep positive and negative separate; label your wiring runs with their destination.
4. Buy a larger fuse block than you require today so you can expand your power needs tomorrow.
5. Buy as much battery capacity as you can afford in terms of weight, size and dollars. Ensure you have sufficient power storage for your anticipated needs.
6. Buy the right sized wire and fuses for your power load – consult the mfr’s recommendations and qualified personnel to assist you.
7. If purchasing an inverter ensure it will take the peak load of the largest device you want to plug into it; consider how this load interacts with your battery array.
8. Consult qualified automotive or RV service personnel before beginning your electrical project.
9. Failure to properly size or install electrical wiring for your components may result in damage to your components or a fire that destroys your beloved boogie van.
10. Label everything in your power box so you know what your are dealing with when maintenance situations arise. Even though it is nominally 12v DC, certain components in the solar system can produce 600v or more. Exercise caution when working inside your power box.
11. Whenever cutting into the metal envelope of your boogie van, be very aware of what is behind the cut.