View Full Version : [Question(s)] Alternator Carging batteries

04-14-2010, 09:37 AM
I have a 12v lead acid battery and have a permenat magnet alternator.

1. There is no voltage regulation on the alternator.


2. RPM from the engine can and does vary.

3. Voltage will vary between 12-96 volts.

The main question is: What sort of regulation is needed, if any to charge the batteries?

Ideas/secondary questions:

Would a simple diode work? Just let the battery regulate itself? Possible damage/overheating?

If that would not work could a switching regulator be made to take the varing input. Effecincy is the key. 90% or better on a regulator. 10A 12Volt output on regulator would be around max.

04-16-2010, 01:53 PM
Well I researched my own question. And the answer is that yes higher voltage will "charge" a lead acid battery but will do it at too high of a rate for the chemical reaction to keep up and gassing will occure basiclly boils down to a big no no. However I did find that the optimal voltage is 14.4 volts for charging. Still researching the regulation method.

04-16-2010, 03:25 PM
Look here i dont know if this is exactlly what you want but it does charge batteries from a car alternator.


04-28-2010, 02:24 PM
Go to the junk yard, and find a car with an external regulator. Take it, and use that.