I bought way too much wire, and overkill waterproof connectors, but it all works.

I still need to drill a big 3 1/4 Inch hole for the control panel, and attach the voltage meter to something.

I tried adding another battery, but I think it was bad. I swear I checked the voltage(although it may have been months ago), and attached it correctly, but it is showing 0-1v now. It was most likely bad, I know its from an old, failed UPS.

I also tested out using my sub on the 3rd channel, and the two old 6.5 inch speakers on the 4th. It sounds good, but I think it could use more bass. I don't know if bridging the second two channels will make is sound better, or fry my amp, so I haven't tried it yet.