Installing a Solar Electrical System

Before we dive into a quick guide on how to install a solar power system, it is important to note that you may need an experienced electrician to ensure the safe installation and operation of your electrical systems.

If you are not sure of what you need to do, it is possible to suffer electric shock or even cause an explosion! Be sure to work with a licensed, experienced electrician if are not confident in your abilities and want a fully functional and safe solar electrical system in your van.

That being said, most people are able to go from knowing nothing about solar to successfully building out their entire solar setup. 

Components of a Solar Electrical System

Compile a list of all the electrical gadgets that you will be using in the van and calculate the amount of power you need on a daily basis.

This list should include things like your ventilation fan, lights, power outlets, cooktop (if not using gas), and other appliances.

This will help determine the kind of components to buy for your system. If you are not sure of how to calculate your power needs, consult your electrician or use some free online calculators.

Once you have the amp hours you need, it is time to shop around for a battery. Keep in mind that none of these supplies -- batteries, sockets and wires -- are 100% efficient.

Also, these supplies depreciate with time, so it’s best to assume that everything functions at about 50% efficiency.

Choose battery and solar panels with double the capacity of electrical power you need. This allows for contingency planning as well as ensuring continued supply.

The exact capacity of the solar components you purchase will depend on your power usage. Here is a general list of the components you will need.

• Solar kit
• Battery
• Inverter
• Remote switch
• Fuse box, fuse holders, ANL fuses, maxi fuses, blade fuses
• Battery on/off switch
• Bus-bar 
• Lights  - mostly LED packs
• LED dimmer switches
• Socket outlet
• Battery cable
• Strand wire (Black and red)
• 14 AWG wire (both red and black)
• Female quick disconnects
• Ring terminals
• Wire connectors kit
• Cable splice kit
• Smart battery isolator

The tools you will need include:

• A drill
• Electrical tape
• Electrician manual multi-tool

While it seems like a pretty intense list, often solar set-up kits include many of the necessary parts. You may need to buy some additional parts but it is not as intimidating when you purchase the equipment in a package. Just be sure to follow the directions.

Now, you probably want to know how all the pieces work together. Well, the solar panels soak up energy from the sun’s rays. The panels are connected to the charge control, which is connected to the battery that stores the energy. This energy then goes through an inverter before it is let out of the sockets where you can plug in your gadgets. 

Wiring the System

Hiring a qualified, experienced electrician is a must if you do not know how to work with electrical systems, but you can still educate yourself on basic circuitry. There are loads of resources online that can give you the basics of circuitry, complete with diagrams. 

It is vital to have the correct gauge and length of the wiring. The LED lighting wire gauge maybe different from the battery wire gauge requirements; the same goes for fuses. Be sure to check the accompanying manuals when working with an inverter, charge controller, and batteries. Always use the fuse sizes recommended by the manufacturer.

Crimp connectors are the magic that connects all these wires to form a functional system. Crimp connectors can either be female disconnects or ring terminals. All you need is an electrician’s multi-tool and knowledge on how to cut and crimp wires!

Brief Installation Guide

The Solar Panels 

Start by mounting the panels on the van’s roof and wiring them. Parallel wiring is quite common; this is a system where all positive wires run together and all negative wires run together. Parallel wiring helps balance the power supply in case one of the panels is not adequately exposed to the sun. Remember to connect the batteries before hooking up the panels to the charge controller. 

The Charge Controller

The charge controller goes inside the van. Since it needs ventilation to avoid overheating, be sure to leave ample space all around it when mounting.

The Batteries

Remember the parallel wiring? Well, the same system applies to the batteries too. Connect the positive terminals together and repeat the procedure with the negative ones. A quality, right gauge cable is necessary for this step. A 4-gauge wire is okay, but this will depend on the system you are putting up.

Ground the batteries to the chassis of the van. A 2-gauge wire is sufficient for the ground connection. You can screw a ring terminus on the vehicle frame safely using shake-proof lock washers.

Connecting Batteries and Charge Controller

DO NOT connect the charge control to the solar panels while the battery is not hooked up! You can use 8AWG wire to connect the positive battery terminal to the charge controller’s on/off switch. This allows a quick disconnect of the battery if needed.

Connect the inline fuse holder to the other side of the switch using a 4AG wire. The fuse should always match the charge control, e.g. 30A fuse for a 30A charge controller. Connect the positive terminal from the fuse to the battery’s positive. Be sure to have your solar panels fused.

Connecting the Solar Panels to the Charge Controller

Connecting the solar panels to the charge controller involves connecting the positives of both the solar panels and the charge controller together, and the same for the negative terminals. This completes the system so that the batteries are now being charged! Once this is done, wire the load terminals to the controller.

Installing the Outlets

This is the simpler part of the electrical works. Hopefully you have planned out the locations of your outlets and have left the wires accessible. Start by carefully drilling holes at your preferred locations. Connect the back of the outlets by crimping onto the black and red wires. Attach the other positive wire to the fuse box and the negative to the bus bar with a ring terminal. 

Powering the Fan

Crimp the positive and negative wires to additional pieces. Pass the positive wire through the fuse box and the negative one to the bus bar. Use a ring terminal to connect the negative to the common bus bar.

Connecting the Lights and Switches

You can use twist connectors to attach the fan and lights to the right wires. Be sure to secure the connectors so that they do not become loose with vibration. You can use electrical tape to secure the connectors before hanging the lights in place. Once the wires are connected and well labeled, hook up the switches. You can opt for three-wired switches – negative, positive and ground wires.

Wiring the Inverter

Once you decide where to place your inverter, connect it to the battery. If you want the ability to turn the converter on and off, run the positive wire through an on/off switch then through an inline fuse before connecting it to the battery. This will allow you to switch it on and off whenever the need arises.

Turn It On!

If you have done everything correctly, this is the point where everything starts working: the lights, the fan, etc. Unfortunately, it is also quite possible that nothing will happen when you hit the switch. If that’s the case, go through your circuit and check where the connection may be incomplete. Check to ensure the charge controller and the panels are well connected and that all the fuse boxes are in place. Go through the circuit slowly until you locate the issue and fix it.

Final Check

Remember that your solar and electrical system is connected to a moving van, so it is vital that all these gadgets are firmly secured in place so that no amount of movement and vibration will distort the connections.  This also assures safety. If you have followed the instructions that come with the appliances and still have power issues, consult an experienced electrician.