Storage and Operation
Another area where battery backup power surges ahead of gas generators is in its silent, emission-free operation. Also, battery systems are discreetly stored or installed inside the house, where they plug into any wall outlet for charging (when the grid is up, that is).
Gas generators of all types must be operated outdoors, due to their toxic exhaust, and they can be quite noisy -- particularly portable units. Gas generators also need a reserve supply of fuel, which requires outdoor storage as well as conditioning additives and/or periodic replacement of the fuel so the gas doesn't go bad while it sits.