content: It says it runs 120 minutes at full load. Mine did about 7 minutes at 35% load... at that point we were at 30% level - the so-called "deep cycle" battery discharge according to the control software.Think about it: 830 watts is about 70 amps at 12 volts. 70 AMPS! A car battery might last an hour if it was new at this load, and belive me, the batteries in this are a LOT smaller.The spec sheet that comes wtih the unit says 120 minutes at MIN load - i.e., nothing connected![...]