Hi Doug. Even with the 14% inefficiency of a modified sinewave inverter (which would be fine as long as the chargers are transformer based, not switch mode), the current draw would not exceed 2.54 amp dc. So a 85 amp battery would last ((85/2)/2.54) 16 1/2 hrs. 2 charges would last 8 1/4 hrs etc etc. I can get you a decent leisure battery and inverter, so the battery could be charged up the night before? Saves buying, storing and carrying a geni.
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