Bad charging update

A while ago I posted an appeal concerning the lack of charge on my 90. The
warning light was extinguishing as normal but the battery was slowly going
flat. I checked the charge voltage and it never got above 13.2. It was
suggested that I clean the alternator connections, which I did. Charge
voltage is now 14.2 max. Still quite low but it seems to be enough to keep
the battery topped up now. So, thanks for all the advice, saved me £70 for a
new alternator.

Peter wrote:
> A while ago I posted an appeal concerning the lack of charge on my 90. The
> warning light was extinguishing as normal but the battery was slowly going
> flat. I checked the charge voltage and it never got above 13.2. It was
> suggested that I clean the alternator connections, which I did. Charge
> voltage is now 14.2 max. Still quite low but it seems to be enough to keep
> the battery topped up now. So, thanks for all the advice, saved me £70 for a
> new alternator.

14.2 is bordering on too high - 13.8V and above is more than sufficient
to charge a battery and anything much above 14.2V tends to boil all the
eletrolyte off.


--
EMB

On or around Fri, 31 Mar 2006 15:36:28 +1200, EMB <[email protected]>
enlightened us thusly:

>Peter wrote:
>> A while ago I posted an appeal concerning the lack of charge on my 90. The
>> warning light was extinguishing as normal but the battery was slowly going
>> flat. I checked the charge voltage and it never got above 13.2. It was
>> suggested that I clean the alternator connections, which I did. Charge
>> voltage is now 14.2 max. Still quite low but it seems to be enough to keep
>> the battery topped up now. So, thanks for all the advice, saved me £70 for a
>> new alternator.
>
>14.2 is bordering on too high - 13.8V and above is more than sufficient
>to charge a battery and anything much above 14.2V tends to boil all the
>eletrolyte off.

you'll find typical alternators put out anything up to 15V when running fast
and under light load - put the headlights and heater blower and wiper motor
on and measure it... and heated rear screen if available.

I don't think the voltage regulation on automotive generators is all that
precise.

I once, on one of my cars, fired it up, moved it about 20 feet across the
yard and left it running. As it was damp sort of weather at the time, the
HRW was already on. After a minute or two the car stopped of its own
accord, which I thought little about, then after about 10 minutes I went
back to it and found that the HRW (plus other ignition style loads) had
flattened the battery - but just leaving the ignition on doesn't normally do
that in 10 minutes, the HRW takes a fair few amps.

--
Austin Shackles. www.ddol-las.net my opinions are just that
"The great masses of the people ... will more easily fall victims to
a great lie than to a small one" Adolf Hitler (1889 - 1945)
from Mein Kampf, Ch 10