jkwilson wrote:
What exact battery charger are you operating?
The battery resistance is a non-issue. Amps are amps on the DC side of the circuit. What may be happening is that the charger output voltage may be changing which can change power output and requiring more or less input power.
An inverter generator is power limited at reduced RPM. The generator creates DC power that supplies the inverter. Lower RPM means lower generator output power and less power available from the inverter.
It is a PowerMax adjustable voltage. You set your charging voltage at 14.6, say, and it holds that voltage. Very steady. It is current limited at just over 75 amps. (You can usually get a few more than rated amps with any converter if you have short fat wires to the battery)
The Kill-A-Watt shows it is pulling just under 1700VA while it is doing 75 amps when set to 14.6v and the battery voltage is of course rising while the 75 amps keeps going in.
The battery resistance rises as battery voltage climbs and at some point the converter amps start to taper. When they taper, output watts drops and so does input VA required from the gen.
In this case, it only ran for a few minutes with no red light and then it started flashing, so not enough time for battery resistance to climb? The gen would have warmed up some more (I had it running well before loading it though) and the current going through the wires and the battery would warm them up a bit too. Don't know if that would increase the VA required in those few minutes. Something did.
