Charging system probs

[markp...@videotron.ca]

Need a good electrical guy to help me out. I have a 1984 944 na.
Bought a new battery last year and noticed it wouldnt hold its charge
after a few months. Returned it and got a new one. Problem solved. Car
started and ran great. Few weeks later (after not even driving the
car) i noticed car was turning over very sluggish. Checked battery and
sure enough it had drained off to approx 12 V. Recharged it over and
over but it still keeps discharging. Checked parasitic load. 20 ma`s.
Alternator putting back about 14.6 volts. My charger cant seem to put
back more than 12.3 volts back into it. Anyone have any advice.
Battery is a generic brand from auto mega store.
thanks

Mark

[darthpup]

I also own an 84 944. You should not have any "parasitic load" on the
battery. I don't and my battery holds its charge.

[Dieter]

darthpup wrote:
> I also own an 84 944. You should not have any "parasitic load" on the
> battery. I don't and my battery holds its charge.

I have a 5/85 944 and the clock draws 6mA with 10mA pulses every second.
So there is a small load (it is not parasitic it is there by design).
If you have 20mA load then in about 50 hours (~2days) you will drain the
battery 1 A. So a 40 amp hour batter will be flat in about 80 days if it
is not periodically recharged (this is neglecting self dicharge of the
battery).
When charging a battery it is a good idea to monitor the charge current.
The 12.3v may be due to the charger supplying its max current. If this
is the case its output voltage will then drop, which is to be expected.
If the charger has 12.3v without being attached to a load then it is
most likely faulty.

Hans

[Alec]

I have not measured my 944 but it holds it's charge for at least 2 months of
no use.

20ma is not unusual for the parasitic load remember you probably have the
clock and the radio and the security alarm.

The alternator should put in about 14 volts with the engine running at about
1500 to 2000 revs and the headlights on. More than 14.5 is
suspect(overcharging) and less than 13.5 also( undercharging).

Any charger from the mains worth it's salt should show 13.5 to 14 or higher
after a few hours. More than 15 will overheat the battery and "boil" off the
electrolyte if left on too long.

Alec

<markp...@videotron.ca> wrote in message
news:b00cb096-269e-4f3a...@w7g2000hsa.googlegroups.com...

[William Noble]

others have made measurements and given you some advise

If you have a security system, disconnect it - I've seen several 1980s
vintage systems fail (including on my 85.5 944) where they start drawing
excessive current and kill the battery. the factory system doesn't seem to
do this, but the after market ones do.

<markp...@videotron.ca> wrote in message
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