[busterbrown]

First off, 6 volt batteries are usually referred to as deep cycle golf cart batteries, the most popular size being GC2. Wired in series, 2 GC2's will usually provide over 200 amp hours. The rule of thumb with any deep cycle battery is avoid dropping below 50% SOC (state of charge). So, this would provide 100 usable AH.

As each persons energy needs are different, 100 amp hours should be enough for 1 or 2 days of general use. General use would be several hours of television time, use of some interior LED lights, USB charging of phones and devices, fridge operation, DC water pump use, and even the DC radio.

If one's needs are much greater than that, the battery bank described above will either have to be augmented with solar power or run time from a fueled generator.

Also, the OEM converter must be up to the task of charging a larger golf cart battery bank. I replaced mine with an aftermarket 60 amp 4 stage charger last year.