A solar charger is now even more cost effective to build as you may think. 6 years ago I looked into adding a solar charger for the 12v side of our old caravan, but the panels were quite expensive at the time, as was the equipment to set the system up. Thankfully, solar has become even more popular now and prices have really come down, meaning that you can buy a 10 watt panel for under £20 and a charge control unit for around a tenner.
What you’ll need:
- Knowledge in wiring up 12v circuits and understanding of currents
- A 12v lead acid battery (deep cycling is better for this but a car battery will suffice)
- Some cable (13 amp will suffice unless you’re pulling high amperage)
- A solar panel (10w minimum)
- A charge controller unit (vital)
- Some fuse connectors (ignore if you already have fitted fuses) and electrical connectors
- Some battery terminal connectors
- Some hand tools including a Philips screwdriver, wire cutter, crimpers
Wiring the solar circuit
It’s vital that you use a solar charger controller in this system. If you don’t, you’re going to end up putting well over 14v into your battery at times which will eventually kill it. A charge controller regulates the amount of power going into the battery to prevent overcharging (I set mine at 13.6v). Do not skip this important bit of equipment!
The charge controller will require wiring in a specific way. This is usually (but not always) carried out by connecting the battery first, followed by the solar panel and then finally the accessory output of the controller (if used). Your controller will provided spicific instructions on how to do this. Here’s the basic layout:
My video below explains how this is done in more detail. Note that I used a controller with 5v USB outputs for easy charging of my phone. This system could be made portable by placing the battery and controller in a waterproof box and then mounting the panel on top of the box. Ideal for wild camping where no source of mains electricity is available and all made for under £27.