You need to measure right at the alternator output stud. If there is not
at least 13.5V there with the engine running you have a real problem.
14v is more typical but VW says 13.5v min.

Mark

Roland wrote:
> Hi folks,
>
> Had a dead battery in town ('89 Syncro).  At home I have now recharged it
> and did a test.  With the engine running (charging) the meter show 12.5
> volts at the battery both at idle and at 2K RPMs.  I read many archives, and
> it seems something like 13.8 volts is more normal, or typical.  Recently I
> haven't driven it much, maybe 1-2 trips into town per week, about 5 miles
> away, usually with 2-4 short stops / restarts.  So I was thinking that maybe
> with this low charging voltage, and many engine restarts, the battery simply
> didn't get enough recharge from driving.  I think it will recharge at 12.5
> volts, but could this mean that many consecutive short trips won't be enough
> to keep it charged?  Or this voltage indicative of a bad or failing
> regulator?
>
> Thank you for any comments.
>
> Roland
>