I made this solar generator to power lights, a radio and recharge batteries for my trip to Burning Man 2008.
1. Sunforce 15 watt solar charger with with 7 amp charge controller - Kragen Auto - $99.99 part #50033
2. Pro X One 800 watt power inverter - Kragen Auto - $49.97 on sale - part #64009624
3. Nautilus Gold 24 NG24 deep cycle battery - $84.99 - Kragen Auto - part #6228613
4. 12 volt outlet (cigarette lighter type) - 10.99 - Kragen Auto - part #6261044
5. Digital multimeter - $2.99 - Harbor Freight Tools - part #90899
6. Crimp style electrical connectors (butt and 3/8" ring) - $2
7. 1/2" plywood (or whatever you have lying around) - $10.00
8. Hinges, handles, latches and screws for the box - $15.00
9. Eight zinc plated "L" brackets - $5.00
Step 1: Buy the parts
I got most of my parts from Kragen Auto. They'll give you a 10% discount if you ask. I had some 1/2" plywood left over from another project to build my box but I saw that RoDuS1488 used a small cooler for his solar generator...that's a great idea, especially if you don't have wood working tools or just can't wait to get the party started. The solar panel comes with a fifteen foot cord that seems long enough to keep the panel out of the shade. Multiple panels can be wired together to get more power. One 15 watt panel barely keeps the battery charged. I think two (at thirty watts) would do a little better.
Step 2: Build a box
I built my box out of 1/2" plywood and reinforced the inside corners with zinc plated "L" brackets. The sides have heavy duty chest handles to carry the generator and the bottom has four zinc plated metal corners to protect the bottom. The lid is held on with two hinges in the rear and one latch in the front. I made the box 1/2" bigger than my battery around the sides and 2" taller. I also drilled one inch holes in the sides to vent hydrogen gas and allow the battery to cool.
Step 3: Connect the wires
Put the battery in the box and connect the wires. I cut the ends and used 3/8" ring crimp wire connectors to run the wires to the battery terminal posts. My deep cycle battery has four posts...two are standard car battery type posts and the other two are threaded studs. I used the threaded studs for a more secure connection. Connect the red terminal from the inverter to the positive post and the black to the negative. The solar panel connects to the battery through the charge controller. This keeps the battery from over-charging. The controller shuts off at 14.2 volts and comes on when the voltage drops below 13 volts. I also added a 12 volt outlet directly to the battery for use with cigarette lighter adapters. There's a two amp inline fuse on the positive lead. I bought a cheap digital multimeter and zip tied it to the top of the battery so I can monitor the voltage usage. I cut the leads and again used 3/8" ring crimp connectors to permanently connect them to the battery.
Step 4: Plug in and enjoy clean, silent power!
I'll use the generator in my dome to run white LED Christmas lights, satellite radio and to charge batteries for my camera and ham radios. )'(
Update: The generator worked great. It never ran out of power. I use it every day at home now.