"sid" wrote in message
...

80 watts at 120 volts is the same as 960 watts at 12v. add in the losses
in
the inverter, and you're gonna need a large battery

Nope !
80 watts is 80 watts
P = I * E
or I = P / E
80watts / 120volts = 0.66 amps
80watts / 12 volts = 6.6 amps

I never figured I would ever get more than 1.5 to 2 amps from dry-cell
or alkaline batteries.
But I didn't expect it to be that poor.

Its not only for a display, its a contest !

The watts is the same for any voltage as you noted. Just add some for the
loss in the inverter. Might as well think of it as 10 amps to allow for the
loss in the inverter.

That means something the size of a lawn mower battery to run it for an hour
or so. I have a rechargable to start a 5 KW generator. It is rated 15 amp
hours. It is about 4 x 4 x6 inches. This would run your lights around an
hour and a half, maybe slightly more.