2001 Rialta battery won't hold a charge (even a new battery).

(Maryland)

Engine battery loses a charge evidenced by inability to start the engine (not even a click of a solenoid activating), no digital gauges, no radio. Have tried jump start, no joy. Have tried battery charger, no joy. Have tried emergency deep-charge battery back-up, no joy. Understand there may be a conflict between engine battery and the deep-charge battery. Both batteries are probably original (10year old) but they test as being intact.

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2001 Rialta battery won't hold a charge (even a new battery).

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Jul 24, 2010

Batteries at end of their life...
by: wil

Any lead-acid battery at the end of it's life will take a surface charge, but be unable to pass sufficient current to power anything.

That said, you may still have a problem inside of your Bosch alternator with integral voltage regulator. A single diode, failed in the closed position, might result in both batteries losing their charge to the other. A lot of things have to go right (or wrong, depending on your POV) for this to occur. It's unlikely, but possible.

Frankly, 10 years is on the far side of lead-acid battery life, particularly if impeccable maintenance has not been the norm. I submit that replacement is probably in order, followed by rigorous testing by a VW mechanic or alternator specialist, with a follow-up hunt for phantom drains on the house battery. If all is clear, you probably have licked the problem. Give serious consideration to acquisition of a 3-stage charger/ battery minder for the house battery to replace the original 2 stage charger section in the converter.