Problem With My Other Car

[pezzonovante88]

Last night after a wedding reception I went to start my 1998 BMW 328 and it wouldn't start due to a dead battery. I had it boosted and it started right up and I drove it home. I thought that perhaps the door didn't latch resulting in a drained the battery. But this morning the same thing happened. I put the battery reader on it and it read about 12.1 which is okay. Could this be an issue with the battery itself, or is there another problem? Any advice would be greatly appreciated. Thanks!

[Dangermouse]

Just because it is reading 12V doesn't mean it has the power to do anything. Take to to autozone etc and get it load-tested.

How old is it?

[Cory W]

Being in Canada, check for battery freeze, and any break/compromise of the battery connectors or wiring. Either of those can provide just enough power for courtesy lights, but not enough to turn it over.

[Bruce Johnson]

Try cleaning the battery posts and terminals with a wire brush.

[DMCMW Dave]

Turn on the lights and check the battery again. I'll bet it's a lot lower than 12.1 V

How old is the battery?

[pezzonovante88]

Turn on the lights and check the battery again. I'll bet it's a lot lower than 12.1 V

How old is the battery?

The battery is at least 5 years old.

[refugeefromcalif]

The battery is at least 5 years old.

At 5 years old, I'd replace it for Peace of Mind.

My '05 Grand Caravan's battery lasted 7 years but, It was Very weak when I did.

George

[Jacko]

... a five year old battery has lived it's life. Time for a new one.

[DMCMW Dave]

I've seen (personally) OEM German BMW batteries last 8 years. The replacements NEVER last that long.

A BMW alternator failure before 150K miles is rare. Don't get me started on their cooling systems though. . .

[pezzonovante88]

I've seen (personally) OEM German BMW batteries last 8 years. The replacements NEVER last that long.

A BMW alternator failure before 150K miles is rare. Don't get me started on their cooling systems though. . .

How would I test whether the problem lies with the battery or with the alternator?

[pezzonovante88]

After doing a little research, it's probably just the battery. I'll get a new one tomorrow.

[Jonathan]

After doing a little research, it's probably just the battery. I'll get a new one tomorrow.

At 5 years old, this is likely a good thing to do.

A guy I worked with once said he replaced the battery on his wife's car at the 5 year mark no matter what. He said the $100 for the battery (or $20 per year in maintenance costs if you look at it that way) was nothing compared to just one time of his wife getting stuck in the mall parking lot in the winter and not being able to get home. My guess is the $100 was well worth the trade to avoid that phone call/conversation with an angry wife.