Strange electrical/starting problem - 90q

Huw Powell audi at
Mon Sep 18 21:35:37 EDT 2006

> I'm trying to decipher this one and the best I can come up with is a weak
> battery.  But thought I'd inquire here before just replacing it.
> Symptoms:
> After several days of starting the car, it finally will slowly grind down to
> a no start/dead battery.
> However, after charging, the battery holds at a steady 12.7x volts even for
> a couple days which would indicate to me that there is nothing in the
> electrical draining the battery.
> So, I thought it was the alternator.
> But when running, the alternator is putting out 14+volts - the battery just
> doesn't seem to take the charge (have to actually put it on a trickle charge
> overnight and things are fine for another couple days).

I'd better throw in my .02 now since you are about to buy a new 
battery... I agree with your statement that the battery seems good.

Your alternator also seems good (that 14 volts).

The problem seems to be that alternator juice is not recharging the 
battery.  I would suggest carefully checking all the big + wires and the 
grounds, or even simply undoing and cleaning them all.

You should see that 14+ volts when running across the battery terminals 
- if the trickle charger works, so should the alternator if it can hold 
that voltage and get it through the wires to the battery.

At the least, before buying a battery, have yours load tested.

You can also have the starter cranking draw measured at any competent 
garage.  I once had a starter pulling over 200 amps.  It worked ok, but 
was murder on the battery charge cycle.

Huw Powell

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