Charger amps

[sailorboy1]

I've noticed that running my generator with only the battery charger on that the AC amps are 6, but the DC amps going into my battery per the battery monitor is only about 30. So that's 690W being supplied to the charger, but only around 420-450W going into the battery.

Can anyone explain where the extra watts are going? The charger power factor is 0.89

[S/V Illusion]

No charger is 90% efficient. The principle consumer of what you perceive as the excess power is used generating heat. That's why most chargers have a fan (which also consumes power).

[smac999]

do you only have a 30a charger running off a gen? that is a huge waste of time and fuel.

[sailorboy1]

Originally Posted by smac999

do you only have a 30a charger running off a gen? that is a huge waste of time and fuel.

100 amp charger capacity, battery acceptance controls amps in

[skipmac]

In simple terms, the power factor is how efficiently the AC power is used by a device. Related to the phase difference in phase of the AC volts and current.

The power factor doesn't tell you the efficiency of the conversion from AC to DC in the charger although it does have an indirect effect.

And, yes the difference is dissipated as heat.

[sailorboy1]

My generator right now is supplying 9.2 amps at 115 VAC, the battery charger is putting out about 47 amps at 14 VDC.

Is this normal for a battery charger? I don't have any experience with the battery charger except recently with the generator.

[smac999]

seems normal. the mastervolt 12/100-3 draws about 16-18a at full blast.

which is exactly double both your vaules.

[tanglewood]

Originally Posted by sailorboy1

My generator right now is supplying 9.2 amps at 115 VAC, the battery charger is putting out about 47 amps at 14 VDC.

Is this normal for a battery charger? I don't have any experience with the battery charger except recently with the generator.

That's only about a 60% conversion efficiency which isn't very good, but it is what it is. I would expect to see something in the 80-85% range for a charger, but clearly it's not a big priority for designers.