How about a 4 pound "battery"?

[nookandcrannycar]

Originally Posted by CTScott

The voltage regulator module, within the alternator, would be the first to fail if the current draw by the caps is too much. Thus far I have seen a peak current draw of 45A, which is well within the 70A rating of the stock alternator.

The zener diode is not a bad idea to prevent damage from over voltage, but there again the voltage regulators in modern cars generally prevent that type of failure mode. I will eventually add a large rectifier diode to the pack to prevent the possibility of reverse polarity, as that would result in the most catastrophic failure.

I have a somewhat related question. IIRC, it was the voltage regulator that was the 'failure issue' re the alternator on 2007 (only) Yarii. Sears put a remanufactured alternator from a local company (this happened near Minneapolis) in my Yaris. Would that remanufactured alternator have to have been from a 2007 to work properly long term? If not, I assume I could currently have a 2008, 2009, or 2010 alternator (I did this replacement in 2010)? Is there any way I can tell the 'model year affiliation' (for lack of a better phrase) of this remanufactured alternator that is currently in my Yaris? (Sorry re the extra question).