A battery in the house is not a good idea because of the gases it gives off , if your serious about a power thing how about just buying one of those UPS gizmo's, it works as a surge protector and will run a small 110 to 12 power supply for quite a while. I have that setup here, I usually run a Tripp Lite 70 for all my accessories and radios, but I have a small pyramid 4 amp 12 volt supply that needs 110, one time about a year ago I pulled the plug out of the wall and used a Magnum 257 with about 25 watt output for well over 5 hours and still had good output from the radio. I think I paid like 75 bucks for the UPS that I have, has 6 plugs in it and I have really never killed it to the point it was dead except when I first got it.
