I found an 800watt inverter at Lowes

http://www.lowes.com/pd_328619-89606-PC ... facetInfo=

I have a few 12 volt tractor batteries to use also. I'm working on designing a circuit that would switch power automatically when either I have a power loss or the battery is at full charge.

I'm working on a circuit design but I'm just curious if anyone has wiring diagrams already for something like this.