Summary
The solar and electrical system on the van was one of the most daunting tasks during the entire build process.
If I’m being honest
This was the project that I had the least amount of knowledge on, so it required the most amount of research. So hopefully this break down of my electrical and solar system will help you plan out yours.
One of the hardest parts of sizing your solar system is to determine just how big of a system you need to meet your daily usage. The reason it takes so much time and effort is because most people have never really had to think about their daily power consumption.
So if you want to be lazy and avoid the need for all calculations you can just copy my exact system and never have to worry about it. I run;
- Electric induction cooktop,
- Fridge / freezer combo,
- Kettle, blender,
- Lights, water pump,
- Charge a computer,
- Charger cameras,
and many other things and have never had any issues.
Tools used
When building out your van you will learn that the majority of the wiring in these conversions are 12v wiring. This is done for many reasons but the main reason is that the majority of 12v appliances are drastically more efficient. This garage of wire is overkill for 99% of applications in the van. I used it mainly because it’s a very durable wire that made all my connections easier to manage.
For all of the outlets in the van I just used standard 14/2 House wiring with a ground. Wire is relatively inexpensive and so are outlets so I put outlets everywhere I thought I might need one. My van has 6 outlets installed in it which allows me to easily charge any device no matter where I happen to be sitting when working in the van.
On my van I run a 110v electric hot water tank. Due to the larger power draw in comparison to all of the other AC circuits, it requires a larger gauge wire to handle the increased current is used. For my build I only needed about 10ft of this wire which I was able to purchase by the foot off a reel at Home Depot.
The solar panels that I ordered came with a fairly standard 10 gauge solar wire so I purchased more of the same wire that I used to run the wire from the panels into the vehicle. Lots of sites online have pre made cables with the proper connections on them. For my build I was able to locate a local solar supply store and have them cut the cables to my length and install the ends for me.
In my build I used (2) 6V AGM batteries and to connect the batteries I used 4/0 welding cable. Welding cable is much easier to work with due to its increased flexibility and can be picked up from most battery supply stores. The one thing to note is when working with welding cable is that you need to install your own cable ends with a crimping tool.
With my electrical install I wanted to have the capability to charge the house batteries off of the engine alternator. In order to accomplish this I needed to connect the house batteries to the alternator. For this wiring run I used 1/0 welding cable and ran it through an ACR to manage the charging between the starting battery and the house battery.
The last wire size that I used was some smaller 6 AWG welding cable. You will see below where this was used in connecting some of the 12v solar components together. I was a big fan of using the welding cable over traditional battery cable mainly due to the increased cable flexibility making it easy to fish around and make it look neat.
For most of the 12v wiring work, I used crimp on connectors. In my build, a combination of blade and ring style connectors were used. When you're buying these types of connectors, make sure they're matched to a range of wire sizes to ensure you get the proper connector size for the wire being used on your build.
When dealing with the welding cable, you can just purchase standard sizes that already have the ends installed on them. I wanted to have the flexibility of changing the wire path and cutting the cables to the exact size needed. You'll find that you might adjust where certain components are going to be positioned. Having the ability to adjust the cable length makes this process much smoother. When using crimp on ring terminal connectors, the terminal comes specific for the wire size they're being crippled on to. Also, you need to know the lug size so the right terminal diameter is used. Making sure you get all the right sizes of connectors can be a bit of a pain to plan out but just sit down with a piece of paper and map it all out and you shouldn’t have any problems.
An MC4 connector is used to join the solar panels together and also to bring the solar power into the vehicle. MC4 connectors are a mechanical connection that can easily be taken apart or clicked together. Full disclosure: I have no idea how hard working these connectors are because I bought the solar wire with the ends already installed.
The final type of connector that I used in a few places on the build was marettes. I only had to use these in a few places when running the 110v wiring outlets. I don’t love using this type of connector but for my requirements it worked fine. I just made sure to tape up all of the fittings once attached to ensure they don’t fall off when I'm driving.
An ACR is an Automatic Charge Relay. This unit allows you to connect your house batteries and engine-starting battery together safely. The benefit of using this unit is that it has the ability to intelligently tell when your vehicle battery has reached maximum charge, then it will begin to send charge to the house batteries. For my system this has been a total life saver and I have barely had to worry about my available house battery power. My van has a lot of high energy consuming devices (fridge, cooktop, hot water tank) and so far it’s worked out really well.
Using (2) 260W 24V Panels, I have 520W total solar power on the roof of my van. The reason for going with a 24v panel over a 12v panel is because the cost was roughly half the price for the panels and my charge controller can handle both so I opted to get the less expensive panels. Also when I designed my roof rack on the vehicle I made it so that it can also accommodate 320W panels so if I ever find myself needing to generate more power I can increase the solar array from 520W - 640W without any drastic changes to the vehicle.
When it comes to batteries, you have a ton of different options that you can choose from. Originally I had looked at using Lead Acid batteries so I could save a little bit of money but after more research, and the potential of having harmful gases escape into the vehicle, I went with AGM Batteries. The batteries that I decided to go with were (2) 6V 335Ah AGM Batteries made by Fullriver. With AGM batteries you can safely discharge them to 70% on a regular basis and its fine to take them down to 50% every couple weeks. That means that I can safely use between 100 - 150 aH of battery, which for my power consumption has been plenty.
I decided to use a lot of the Victron Energy solar components on the van. The Battery Monitor that I went with is the BMV-702 from Victron Energy. In simplest terms, a BMV is like a fuel gauge for your batteries. It will tell you the voltage, current, percent of battery remaining and ampere-hours consumed. The main reason that I went with the Victron BMV is that it also comes with a Bluetooth capability that allows you to get all the information off the BMV directly onto your phone. This feature is really not necessary but for a guy like me who is attracted to all things tech it was a must-have on my build. When installing the BMW you will also need to install the 500A/50mV shunt provided in order for the BMV to function properly. Basically the shunt allows measurements to be taken across two points in the circuit. The resulting information displayed on the digital read out, without the shunt in the system the BMV, would not be able to acquire the necessary information to the user.
The Battery Monitor that I went with is the BMV-702 from Victron Energy. In simplest terms, a BMV is like a fuel gauge for your batteries. It will tell you the voltage, current, percent of battery remaining and ampere-hours consumed. The main reason that I went with the Victron BMV is that it also comes with a Bluetooth capability that allows you to get all the information off the BMV directly onto your phone. This feature is really not necessary but for a guy like me who is attracted to all things tech it was a must have on my build.
I consider the charge controller as the brain of the solar system. This unit is what manages how much charge you're going to be putting into the batteries. I went with the FM60 Charge Controller from Outback simply because... well... A friend of mine had the exact same one in his house and he was very familiar with it so he was able to help me install it as well as troubleshoot any issues I might have while on the road. The FM60 charge controller also allowed me to have an AUX load off the controller which was required to run my hot water system in the fashion I had planned.
General use enclosure for retrofits, small inverter disconnect, PV disconnect, AC or DC distribution or other uses. Accommodates up to four panel mount type breakers from 5 Amps to 100 Amps. I used this box in my solar system to function as a shut off the the Charge Controller, Solar Panels and as a main disconnect on all 12v circuits in the van.
These busbars are designed to fit inside of the Midnite solar breaker box and snap in place. With all the wiring on my system, I only placed the Red Busbar inside the breaker box and the black one outside the box to leave some more room for wire in the box.
Using a busbar is very similar to using a terminal block above. The main difference is that with a terminal block your circuits are kept separate where as with a busbar everything is combined. In my system I used a busbar on both the negative and positive side to keep the wiring neat and easy to troubleshoot. Using the busbar allowed me to run a few positive wires from the 12v fuse panel to the upper control panel, connect them to a separate busbar, and wire many electrical components off of that bar.
I ran power to this Blue Sea 12v fuse panel from the 12v breaker box. This panel allows for easy circuit management and to have these different circuits fused independently. By splitting up the 12v circuits you have inside the van it will make troubleshooting things in the future much easier. This particular fuse panel also had a nice negative busbar section at the top, making it easy to combine all the ground in the circuit.
A terminal block is a really good way to keep your wiring neat and easy to follow. Since the majority of my wiring went from under the passenger bench, up to the control panel then out to the electrical device, I decided to use a terminal block in each location to terminate the wire in that area and keep the wiring as neat as possible. Electrical terminal blocks provide a convenient way to connect individual electrical wires
I decided to go with a Battery Based Inverter Charger for my build. An inverter’s main job is to convert DC power produced by the solar array into usable AC power. I wired as many of my electrical items with 12v power such as lights, fridge, fans, backup camera, etc. For the items that require AC power I decided to go with an Inverter Charger. The inverter charger not only produces AC power to be used in the vans standard outlets but can also be plugged into any power source and used to top up the vans house AGM batteries.
I used a 400A ANL fuse from Blue Sea to protect the system. A fuse is basically a piece of wire designed to melt and separate in the event of excessive current. A fuse is always connected in series with the components to be protected from over-current. I bought 2 fuses just so I had an extra in case anything ever happened.
The fuse above that was purchased requires a special holder in order to properly use the fuse.
The RTS and a Remote Temperature Sensor is not something that comes with the charge controller but needs to be purchased. The RTS helps the charge controller monitor the temperature of your batteries to avoid any risk of over charge and potential damage to the batteries.
I went with this breaker box to control the 110v aspects for the wiring in the van. I used (2) 15A breakers to support the 2 outlets circuits in the van, one 20A breaker for the hot water circuit and then a double pole 60A circuit to function as the main disconnect on the whole system.
If you're familiar with my build you'll know that I used a household 110v point of use hot water heater. This type of water heater has a very hefty power draw and under normal circumstances my van wouldn’t be able to handle it, but with the auxiliary load on the charge controller and this relay I am able to take the excess power from the panels that would typically be wasted when the house batteries are full and divert that water into the hot water tank.
I installed a few 12v outlets to plug in the 12v fans that I purchased as well as one in the fridge sliding cabinet so I would be able to plug in the fridge and have the outlet out of sight.
These are 100% a 'nice-to-have', but can overkill for most people. When I open and close the doors for my wardrobe and back benches, the lights go on/off automatically. It’s a nice feature for sure but definitely not required. One thing to note is that they make two types of magnetic switches, 'normally open' and 'normally closed'. For this application you want to purchase the 'normally open' switches. These switches will function so that when the two magnets are touching the circuit will be closed and the lights off… (Door closed) when the door is opened and magnets are pulled apart the lights on that circuit will turn on.
Similar to Zip Ties, using Electrical tape helps you keep all of the wiring neatly organized and stored properly. When possible, I like to use heat shrink instead of electrical tape but both have their need.
Outlets in the van are something I might have goen overboard with... I think I have 7 total. But its really handy to have outlets everywhere you need them and I upgraded to the USB outlets to help with charging all of my camera gear and electronics.
Rather than having the switches in my van scattered throughout, I wanted to centralize them in a neat and organized upper control panel. Having all the switches all in one place allows me to quickly and easily check what’s on and off, without jumping all over the place. Marine rocker style switches such as this make it very easy to install and manage them in a single panel. One thing to note about using this type of switch panel is that each switch has its own pop fuse and they vary from 5-20a ratings… so don’t put the fridge on one with a 5a rating like I did, you will just end up needing to switch it out.
When you're doing electrical work on your van, zip ties are essential. Using zip ties helps you keep all your wiring organized. It's really easy for your wiring to become a mess. This not only makes your electrical impossible to diagnose but it can also be potential dangerous as loose hanging wires could cause a short.
Heat Shrink is something that many people over look but if you're trying to make your work look as professional as possible, then using heat shrink helps to clean up all connections and ensure you wont have any loose connectors.
