Since upgrading from my 45 watt Harbor Freight system that ran flawlessly for 6 years to my now 200 watt system I decided to make the 45 watt system portable and totally self-contained. The reason is if I have to 'bug out' I can take the system with and keep my "AA" batteries for night lighting, AM/FM Shortwave and two way radios charged and operational if in a grid-down situation.
Two years ago the wiring connection to the PV Cells leaked water and shorted out completely one of the three 15 watt panels rendering that one useless. If you install your own system be certain water can not infiltrate the cell area under the glass through the electrical connecting box on the back side of the panel. So the bottom line is, I have just two 15 watt panels equaling 30 watts of charging power. This is plenty for recharging "AA" batteries for radios, battery powered lights or power tool batteries.
This project was less than $40 for the new charge controller and connectors. I had an old but still functional car battery. That's it the total cost!
If I wanted to make a brand new system I'd buy a 100 watt panel from Home Depot and the total cost of a very powerful 100 watt system would be under $200.
This is a very simple project that anyone can do.
Here's how I converted my old panels into a portable system.
The charge controller is less than $20 and as you can see very small. It is rated for 7 amps it can handle up to a 105 watt panel.
The polarized connectors I used for the connections.
Rear view of the panels
Close up of the panel wire showing how I used epoxy to prevent ripping the wires out of the panel connector box
All wires connected and ready to work. The alligator clips attach to the battery. The 12v socket next to them is where I plug in my 12v extension cord.
The 12 foot extension cord I made with two 12v sockets to power the battery chargers and/or radios.
Side view of working panels leaning against my van.
The panels are putting out 17.5 volts.