This Instructable is on how to build a battery power pack that charges from the sun. I built it this past summer to have a portable device that I could run and charge my gadgets on.

Step 1: Wiring Diagram

The first thing I did was draw a wiring diagram.

Step 2: The Parts

Next I shopped around and purchased my parts.
Below is a list of the parts I used.

Solar Panel - - - - - - - - - - - - $68.95
12 volt battery - - - - - - - - - - $58.00
400 watt inverter - - - - - - - - $21.99
rolling toolbox - - - - - - - - - - $22.88
auxiliary 12 volt plug - - - - - $4.87
auxiliary 12 volt plug - - - - - $4.87
14 gauge wire (red) - - - - - $2.48
14 gauge wire (black) - - - $2.48
heat shrink ring conectors- $2.45
3/16'' heat shrink tube - - - $1.99
bridge rectifier - - - - - - - - $1.99
SPST switch - - - - - - - - - - $2.99
utility - - - - - - - - - - - - - - - - $.54
solder - - - - - - - - - - - - - - - $1.49

total - - - - - - - - - - - - - - - - - $197.97

My battery is a 12 volt deep cycle battery. Deep cycle batteries are
made to be fully charged and discharged; unlike car batteries which
are not supposed to be fully discharged. The battery is rated 75 amp hours.

The inverter converts the battery power (DC) into regular AC power.
The inverter is rated 400 watts.

I bought the solar panel at a farm supply store.
The Solar Panel is rated 5 Watts.

I bought this toolbox because I thought everything would fit in it well,
and it had wheels which would make it easier to transport.

Step 3: Battery Mount

I built a battery mount out of 2X4's to hold the battery in place in the toolbox.

Step 4: Pre-Wiring

Before I started wiring I had to put in a utility box for all the
connections. I removed three of the punch outs on the utility box;
the middle bottom one, the middle side one, and the one end one.

I screwed on and tightened a compression fitting on one end.
That is where the wires going to the 12 volt plug will go through.

Step 5: Installing Power Input Plug

Next I cut a hole for the input power plug. I mounted it so that
the connection end of the input plug would go directly into the
utility box.

Step 6: Hole for Battery Wires

Then I cut a hole under the utility box for the wires going to the battery.

Step 7: Preparing the Wires

In preparation for soldering, I crimped ring conectors on one end of both the positive and negative battery wires. Once they were on, I used a lighter to shrink the heat shrink tube on the ring conector.

The 12 volt plug I bought came with the 2 wires I needed, but because the power input plug went right into the utility box I didn’t need the wires to be so long, so I cut them really short and stripped them off.

Step 8: Soldering

I ran the battery wires up though the hole in the bottom of the utility box and soldered everything together. To keep them from shorting out I put heat shrink tube on all the connections. Next I tightened the compression fittings to prevent the wires from being pulled out. Since all the connections in the utility box had been made, I screwed the lid on.

Step 9: Installing the Power Output Jack

I found where I wanted to mount the 12 volt power plug, drilled holes and bolted it on.

Step 10: Wiring for the Inverter

First I drilled holes and ran the two wires through. Then I cut and stripped the wires just long enough to reach to the battery from the inverter. After that I crimped small ring connectors on the inverter ends of the wires and large ones on the battery ends. Once both ends of both wires had ring connectors, I shrunk the heat shrink with a lighter.

Step 11: Finishing Up

When you are finished, plug it into the solar panel and charge it. Once it's charged you'll be able to use free power from the sun.

If you have any questions I would be glad to answer them. Also feel free to post pictures of your own creations.