Any Electrical Genius's here?

[ocuyler]

The 130 min. reserve is for a NEW battery at 80 degrees F at 25 amp draw, before discharging to 10.5 volts. At 2.75 amps, that will give you 19.5 hours. That's optimum/ brand new.

Your battery has a capacity of approximately 100 amp/hrs. A rule of thumb says not to discharge more than 50%, or 50 amp/hrs. At 2.75 amps per hour, you will have approximately 18 hours.

However, in the real world, those efficiantcies rarly come true do to amp leaks in bad connections, incorrect wiring, higher loads than rated, temperature, etc. So, I agree with PipeDreams: 7 or 8 hours. Do the timer thing...