Originally Posted by lbrjet
800 watts is a 66.6 amp draw. That will drain batteries pretty fast.
Sure 800 watts is a lot, but you need to consider the duty factor and you can get that from the Energy Star rating of your unit.
Measurements taken at Ambient Temp of 90 F
Annual Power Usage is 539 KWH/Year
At 100% running this would mean 8664 KWH/Year
Thus it really runs 6% of the time...
At 6% Duty Factor it uses 1477 WattsDay
At 6% Duty Factor it 62 Watt Hours, which is about 5 amps average load. That would be 10 hours for a single 100 AH battery to 50%, which pretty much matches what many report.