Quote:
Originally Posted by Whangler
The Victron specs for the charger state a power factor of 1. Does that mean the a/c watt input would equal the d/c watt charging output?
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No, that would be an efficiency of 1.0 (100%). Power Factor of 1.0 means that the voltage multiplied by the current into the charger is equal to the wattage into the unit. It will output less than that wattage, which makes efficiency less than 100% (80-90% is pretty typical, I believe).
Power factor is a measure of the percentage of the current that's in phase with the voltage, and therefore does useful work and/or makes heat within the unit. Pure resistive loads like toaster ovens and space heaters have a unity power factor (1.0), but reactive loads like transformers and induction motors will have a pf value less than 1. So a 1000 volt-amp (VA) load with 90% pf is a 900W load, but a 1000VA load.
Pf matters to generators, for instance, as the unit has to supply the current even though it's not all doing anything useful. Wattage output is what the engine is driving, but total current has to flow through the windings and breakers. Think of that 'extra' current as magnetizing current in the windings.
But it's not a concern for you as the charger has a unity power factor, so all of the current goes toward charging and making heat.
Edit: My 3000W Xantrex inverter/charger has a power factor value of .95 while charging, and max charging efficiency of .85, just for comparison,
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