Gib Bogle wrote:
On 5/06/2012 9:52 p.m., Dave Plowman (News) wrote:
In ,
Gib wrote:
While testing things I noticed my battery voltage was very high (I'd
just been running the engine). With the engine running the charging
voltage is about 19v. A new, probably more serious, problem. It's a
bit of a coincidence, so I'm wondering if they are linked. Could the
high battery voltage have caused the motor to fail? I'm familiar with
low or no voltage from the alternator, but I don't know what can cause a
high voltage.

Assuming your DVM hasn't failed - it is reading some 12.5v from the
battery with the engine stopped? - the alternator regulator has failed.
This is usually internal to the alternator but can be replaced for about
£30 if you can be bothered finding one.

Unless the rear wiper was in use for a long period, it's unlikely this
high voltage will have caused it to fail.


There are a couple of things going on here that I don't understand.
After sitting overnight the battery still reads 18v, engine not started.
This shows on three different scales of the DVM. Not believing it, I
checked with my old analog meter - same thing. How can a 12v battery
hold 18v of charge?
are there not some strange new batteries that do in fact take higher
charge? it might also be pure 'surface charge'. If the battery type has
that effect..




--
To people who know nothing, anything is possible.
To people who know too much, it is a sad fact
that they know how little is really possible -
and how hard it is to achieve it.