Battery depletion issues

paulg22 · Post by **paulg22** » 03 Feb 2021, 15:07

I have a 2012 S60. The battery is about 3 months old.

A few days ago, I got into the car and it was completely dead. I jump started it and went about my business. I drove it off and on for the next three or four days with no problems.

I was running a few errands and on my last stop, I parked, turned the car off and everything went dark. The car was a brick.

I got a jump started and drove home. As of right now, the car is running.

To me, this says bad alternator, but since I haven't had an alternator go bad on a car for at least 20 years, I wanted to get some other opinions before I try to fix the problem. Thanks.

Post by **RickHaleParker** » 04 Feb 2021, 02:37

1. With the engine running, measure the voltage across the battery.
2. 1/2 + hour after you shut the car off, measure the voltage across the battery.
3. Clean and tighten the battery terminals. Oxidation on the terminals will cause a large voltage drop that causes a no crank condition.
4. Check/clean connectors on B+ cable, one end is on the Alternator the other end is on the jump block. Jump block is where the long cable from the battery ends in the engine compartment.

Post by **abscate** » 05 Feb 2021, 04:37

8 years and ~120k miles an alternator failure is unlikely

Follow RHP advice above and check all those electricals. With Covid, if your driving habits have changed like mine, many of us are running in charge deficit from short trips, and might need a charge once a month or so.

paulg22 · Post by **paulg22** » 05 Feb 2021, 12:54

RickHaleParker wrote: 04 Feb 2021, 02:37 1. With the engine running, measure the voltage across the battery.
2. 1/2 + hour after you shut the car off, measure the voltage across the battery.
3. Clean and tighten the battery terminals. Oxidation on the terminals will cause a large voltage drop that causes a no crank condition.
4. Check/clean connectors on B+ cable, one end is on the Alternator the other end is on the jump block. Jump block is where the long cable from the battery ends in the engine compartment.

Thanks, I'll give those a try. I already noticed that one of the battery leads wasn't tightened down, so maybe that was the problem.