Combining the output of two alternators

[murpia]

Hi,
What are the challenges of combining the output of two alternators, running at different speeds, to charge one 12V battery?

In particular, one or other alternator could be stationary while the other is rotating. I don't really see how this is different to a single alternator charging a battery, if the alternator is too slow or stationary the regulator diodes prevent current flowing back from the battery into the alternator. But I've learned to be wary of such simplistic observations...

Thanks, Ian

 

[GregLocock]

If you are feeling cautious fit a blocking diode to each alternator so it can't be back driven. Stick an ohmmeter on a stationary alternator - what does it read?


Cheers

Greg Locock


New here? Try reading these, they might help FAQ731-376

http://eng-tips.com/market.cfm?

 

[LionelHutz]

It shouldn't pose any problem. Every time a vehicle is parked the diodes isolate the alternator windings from the battery and it won't change even when you add another alternator.

 

[Compositepro]

This summarizes the issues.

http://www.amplepower.com/products/dac/index.html

 

[MikeHalloran]

That Ample Power regulator will work, if both alternators have external regulators, both of which it replaces. ... and the Ample Power regulator then becomes a single point of failure.

I wouldn't install it on a boat. There are other ways of getting a tach signal than from the alternator regulator circuit, and boats have enough single points of failure already.






Mike Halloran
Pembroke Pines, FL, USA

 

[murpia]

Thanks for the info. It's not a problem if one alternator does all the work, so that combining regulator would be unnecessary.

Regards, Ian