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).

[CTScott]

Originally Posted by nookandcrannycar

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).

Any year alternator will work, but ideally you want a late 08 or newer to have a post TSB voltage regulator. If yours is remanufactured you would have to open it to check the part number on the voltage regulator to see if it is pre or post TSB.

[nookandcrannycar]

Originally Posted by CTScott

Any year alternator will work, but ideally you want a late 08 or newer to have a post TSB voltage regulator. If yours is remanufactured you would have to open it to check the part number on the voltage regulator to see if it is pre or post TSB.

Thanks so much for the great info! I'd like to know, but not enough to open up the alternator.