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[05omegav6]

Had to get the AA out earlier as the car failed to start after a half hour pause in the sun I'd had the radio and the fan on so not exactly a shock.

Battery checked out ok, so was jump started off a booster, and left to run for a bit. Mr AA noted the following:

Alternator charging at 42 amps at idle.
Battery voltage once charged 13.4 volts.
Engine off initially 0.7amps, dropping to 0.35 once the delay relay switched off.

Car has been fine since, but wondering if the alternator might be starting to get weak? New one was fitted at 95k, now at 220k, battery is a Bosch 65ah, new in 2010 iirc done approx 90k.

[Kevin Wood]

The question is what voltage the alternator outputs once the battery is fully charged. I'd give it an overnight charge using a mains charger then see what the alternator is outputting. 14 - 14.5V without significant electrical loads would be typical. 13.4 Volts is a bit weak and might explain why you're having problems, however, I would expect that the battery was still drawing a significant current which may well have loaded the alternator giving a misleading reading.

Do check the crimping of the battery terminals, though, as this is a common problem.

But.. 0.35A quiescent current is too high. I am assuming it was measured with a clamp meter, which may not be accurate at such low current levels, but that is worth some investigation, IMHO.

Might be worth following this procedure: http://www.omegaowners.com/forum/index.php?topic=90619.0

[allen25]

I'm not sure if it is any help, but I did have exactly the same experience some time ago. Not a rush out and do solution though necessarily but eventually the alternator died and was replaced, so was the original Vauxhall battery. Never had an issue since, but I did need a few jump starts before the alternator diagnosis was complete...got worse over time. Can't remember the mileage at the time but circa 100K for both battery and alternator. Not a technical response but real!

[05omegav6]

Ta muchly

Draw was measured with a clamp meter Also battery initially had a charge of 209 amps, and was 484 after five mins or so running after being jumped. Of the top of me head it has a 650amp capacity

I suspect that the quiescent draw is audio related as the H/U, Source Selector, Radio Booster and DVB Tuner all have a permanent live for memory and an ignition switched feed of those only the DVB has a dedicated on/off switch. Also the Idiot Box is hard wired to the switched live, although the meter/roof sign and two way radio are permanently live they were off at the time and their fuses pulled when the reading was taken  meter switches a relay for the roof sign, and it also has a cut off timer which turns it off after 10 mins unless the ignition is live.

Car has behaved as expected over night the last time it needed to be jump started was at the lakes last year
Again self inflicted, watching the Grand Prix and keeping the coolbox chilled

Battery cables seem fine, underneath as well, not getting particularly warm either