Hi Troy,
I purchased a Battery Eliminator that ran off main power, only 2 weeks ago i modified it to run of my lead acid batteries so i can get massive operating time on it. Mostly I modified it to run my imaging equipment completely off battery so I can remove the Inverter from my set-up.
First run with it was Last Saturday although the clouds got in the way the system worked well.
Link to original supply -
http://www.digitalcamerawarehouse.com.au/prod3451.htm
I purchased mine off EBay and was a bit cheaper than the original.