I made a brief foray into the battery system with a deep discharge 12v marine battery that I attached a female cigarette lighter receptacle... it was kept on a cheap float charger, and when I looked to give it a full charge for Irma, one of the cells had died... lack of maintenance on my part...

I'm old school, and place my emergency power plans on two generators... one an old Honda that has been re powered by a new Honda engine, and the newer Harbor Freight Predator 2200/2000W inverter generator.. both have been converted to work off remote fuel tanks, with squeeze ball siphon for the Honda, and since the inverter has a fuel pump, only needs to be primed... this allows me to run off bulk 5 gal cans... for Irma the inverter was run hard for about a week by a friend that powered two upright freezers and a refrigerator with it...changed the oil and plug and sits ready to go...I can throw it in the utility trailer and hook it to the lawn mower to provide power for neighbors and to use the electric chain saw and pole saw... for $350 it has already paid for itself YMMV