Battery Charger Power Consumption

Dear Sir,

You need to address whether your battery charger is supllied with 3 phase or 1 sinle phase supply. Since the Current rating of the Battery Charger is known if you know the Supply voltage then the KW rating of the Battery Charger can be known.

Best Regards,

N.Suresh

sapan; 8 or 9 amps, at 120 volts, there is a watt-meter called the watt stopper that would record the power usage for around $30.00 USA perry

basic ohm's law

26.5 volts x's 40 amps =1060watts

1060 watts / 120 volts =8.8 amps

It is just about impossible to calculate accurately as you must know the efficiency of the charger and the battery and the "state" of the battery (assuming its Lead Acid, this is changing from 1 second to the next!!)......and you need to have a charger that either switches into trickle charge when the battery is full, or drops off completely....many just continue pumping power into the battery, gassing off the water content and damaging the battery at the same time....

The best way is to measure the battery voltage and the power taken from the mains at say battery empty, battery half full and battery full......take a note of the time taken from start to end for a full charge and that will give you a reasonable idea as to how much energy is required from the mains!!

I gave a GA to Andy for his answer. ashoktoshniwal is also correct in his approach and is good enough for a start to size the cables & fuses.

As is common we need more info. Is the charger a mains frequency transformer unit or a more modern SMPS device? Does it have a power factor control circuit? The power factor on an uncorrected transformer based unit will be horrendous. This will cause the input fuse to trip prematurely.

Regards

Chas