Battery drain overnight, but not always, and in winters

sergio · Post by **sergio** » 12 Oct 2012, 09:26

Overnight my battery goes down to 11 to 9.5 V. But this doesn't happen every day! And I have to use my spare battery to boost.
When it happens, it takes less than of driving to read 12.25 V-12.5V on the battery with shut engine.
It was the same last winter, I found out it was the alternator and replaced it.
Now alternator is fine (produces 14.5V after ignition and with battery detached)
I have done the "remove fuses one-by-one-and-check-the-amperage test" No answer to my problem.
It could be the wiring? But how check those wires? They warm in and out of the body.
And why does it happen in cold weather?
Any light would be much appreciated

02 S60 160K miles

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Post by **precopster** » 13 Oct 2012, 05:17

Did you try the fuses in the boot as well?

Also try completing the circuit between battery post and lead with your ammeter WHILE IGNITION IS OFF (if not done with the ignition off it may blow the fuse in your meter)

You should have a reading of no more than 50-80mA . If this is the case replace the battery. If higher you definitely have current drain from the car's electrical system.

Post by **pikngrn** » 13 Oct 2012, 06:17

If your battery has more than 3 years on it, it may just be the constant drain of all the accessories on it. Just because your battery will recharge doesn't mean that your battery is not bad. Volvos have a lot more going on at night than most cars and add to it that it needs more cranking power in the winter plus it has more harder draining accessories than most any other car on the road. Replace it. My battery always charged up on a charger but the alarm system would suck it dry over night. I stopped using it and it still drained but slower. If you make short trips in the car instead of long ones your battery doesn't charge back like you might think. And you can overcharge a battery to the point of it damaging it.
There are some battery maintenance tips out there to get more life out if your battery when you do get another one, check that brand's website to see how to keep it going longer.

sergio · Post by **sergio** » 15 Oct 2012, 19:12

thank you both;

precopster
I tried all 3 fuse boxes (engine, interior and trunk)
I will give a shot with the ammeter.

Funny that since last Friday it hasn't happened again. Tomorrow it will I'm sure.

pikngrn
Battery is only 2 years old. This week I will replace it with the spare I use to boost in the morning. I will see if the same happens again.

volvodoc · Post by **volvodoc** » 17 Oct 2012, 10:08

there is a software avail at dealer for this problem they will update the cem

sergio · Post by **sergio** » 18 Oct 2012, 11:28

volvodoc, when you say "software available at the dealer" you mean they will sell it to me or they have a software that will resolve the problem by updating the cem?

sergio · Post by **sergio** » 18 Oct 2012, 11:35

Another question;
I read 12.45 V on the battery when fully charged and not in the car.
As soon as put it in the car and connect it, with engine not yet running, I read 11.5 V.
As far as I can see only the trunk lights are on.
Is this normal?

thanks

sergio · Post by **sergio** » 28 Sep 2013, 21:13

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About my sporadic battery drainage.... I forgot to put the epitaph in this thread;
It had to do with wire contacts at the starter level. I had changed the alternator and for some reason (old car/high mileage/impatient-inexperienced mechanic!) there was a screw up.
When I replaced the starter (for other reasons) the drainage stopped.

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Now you know the rest of the story...