Battery seems drained for odd reasons.

vooman · Post by **vooman** » 08 Jan 2012, 11:16

2002 S60. Replaced battery about 4 months ago when I had an issue with the fan running on and on which would kill the battery. That problem's been fixed.

Everything seems fine, except the battery dies for almost no reason. If we stop the engine and turn on the emergency blinkers for just 4 or 5 minutes, when we go to start the engine the starter won't crank. A quick jump and it fires right up.

Even plugging in a cell phone adapter into the cigarette lighter for a few minutes when the engine is off is enough to cause the same dead battery scenario.

Strange because most of the time the battery seems strong and normal. Nice fast starts, strong lights with no dimming. No problem with cold starts etc. The little flashing red alarm light on the dash blinks with no issues. But when the ignition is turned off, and we have anything else turned on for even a few minutes, when we then go to turn on the ignition it's more like we've left the headlights on for hours.

Any ideas where I should look?

Thanks!

draser · Post by **draser** » 08 Jan 2012, 15:08

I'd start with the basic batt voltage measurement/engine stopped, then batt voltage with engine running. It should read 14.3V which will tell you the alternator/regulator are working. Autozone, or other auto parts shops will run this for free. You can visually inspect the batt terminals to make sure they're clean and tight (no white stuff/corrosion).

Post by **jmmxc** » 08 Jan 2012, 15:29

Go to this post: https://www.matthewsvolvosite.com/forums ... =1&t=43813 you will find plenty of advices and clues to guide you through battery draining problems. And there are several other posts covering all aspects of drained battery issues.
Good luck.
jmmxc

vooman · Post by **vooman** » 08 Jan 2012, 21:05

Thanks - I'll go through the post.

I was thinking starter cable, or starter solenoid. One other observation - the digital clock resets when this happens.

Post by **jmmxc** » 10 Jan 2012, 19:13

I wonder whether you have a short somewhere, draining the battery, (I am thinking alternator with defective diodes).
The starter/charger system includes a lot of parts (alternator, starter, cable and grounds...and the battery) that are likely to cause these kinds of intermittent symptoms, some less obvious than others. You will need to test step by step until you pinpoint the failing or defective component, (they are all part of an electric circuit in series).
Hopefully it will be something as simple as a bad starter or battery cable or a bad ground connection, and at worst, a failing alternator.
jmmxc