How's a battery charger charge a battery?
It puts about 14-15v across the terminals of the battery.
How's an alternator charge a battery?
It puts about 14-15v across the terminals of the battery.
So - why can a battery charger charge a battery if an alternator can't
An alternator, at full field can exceed 24 volts., so can a battery charger. the difference is the capacity in AMPS that the two different machines can produce. a shop charger will put out 250 AMPS without a problem. A heavy duty alternator, which is very exspensive, can put out 140 AMPS. If it detects a low battery at this output of AMPS, then the voltage will climb. I have repaired many a vehicle that was damaged due to overvoltage conditions, due to charging or the attempted charging of a low or bad battery. think of it in terms of Watts required to recharge a battery. ALSO, an alternator is designed to operate continuously at 60% of it's maximum rating. The max rating is it's surge capacity, not running capacity. If anyone wishes to charge their battery using the alternator, then they are a gambler. It's like entering a fenced yard with a sign that says," large vicious dog lives here 3 days a week" the question is, what 3 days, and the question will be with the car, will we get lucky? and while we are on this subject of electronics, please do not disconnect the battery of a running car to test the alternator, this is a related myth to the alternator-charging-a-dead-battery myth.
Scotland to London?Hmmmm seems to be a British forum here. Hello from accross the big pond.