Lotus99

I parked the car in the garage overnight, and left the hatch open to air the car out, and all the lights went out after about 10 minutes, so I thought it was safe to leave it like that. This morning, I went to start the car, but got a bunch of errors on iDrive, and car wouldn't start. Maybe the computer never went to sleep while the hatch was open? Weird. Any thoughts?

So I'm waiting for the tow truck to come and jump the car. A few questions:

1. I plan on driving it for about an hour, then hopefully it'll charge enough?
2. I'll leave it overnight on a battery charger.
3. Should I have the dealer do a load test on it after?
4. Any permanent damage caused from this?
5. Does the dealer need to reprogram the battery like it's a new one or anything?

Thanks. Any other comments or something I should do?

phelix

If the battery's charge level drops low enough so that it won't start the car then the battery's days are probably numbered and you probably ought to think about replacing it. Car batteries don't like being deep cycled - they never fully recover. The lights should go off after 30 minutes - sounds like the car shut them off sooner meaning it knew the battery discharge rate was too high to allow the car to start. But if your car is a 2010 that's pretty poor battery life; the battery on my 535d was almost 7 years old when I sold the car and seemed plenty strong.

Lotus99

Lights always go out after about 10 minutes, it's an auto shut off feature, nothing to do with battery being low. Car does it all the time. You can test it on your own car. I did it with the map lights in the back, as my kids typically forget and leave them on, and even they go off.

I was worried that it might be affected... Bummer. I'm inclined though instead of spending hundreds on a new battery right now, to wait it out, but I certainly don't want to risk being stranded when away with the family on a trip or anything...

We bought the car used 6 months ago, so I don't know if this has happened before either.

luigi524td

Your signature says it's a 2010 - Unless it's a high mileage ( < 50k miles) used car you should be under warranty. Don't let the dealer tell you you don't drive enough to keep the battery charged!

vanos

Good post for future reference but I don't know what could have caused this and don't see how an open hatch can drain the battery.

I got my 2007 back in April 2011 and had the battery changed (be precaution) in December 2011 after reading posts of people with issues. I opted for a 7 Series battery (higher charge than the 5)...

Lotus99

Yeah, it could be a total coincidence I suppose, as I'm pretty sure I've left the glass part open overnight before with no issues... And you'd think that if the ECU wasn't going to sleep because of that (all I can think of, since the lights were all off), then the same issue would have presented itself with an open glass too. Sucks, because sometimes when the car is wet inside from a wet dog or jackets, I'd like to leave windows door and hatch open to air it out overnight in the garage.

I recall you swapping your battery, did you do it at the dealer in the end, or private (IIRC) and how much was the whole bill?

I'll try to push them to swap it out as it must be defective. My car's only got 20,000 miles on it. We do on average probably 30 miles a day.

tom_il

Actually today i left the tailgate open and noticed after a while (not sure how long) the car was in sleep mode as the shifter and window lights where off. This surprised me as I didn't expect this.

vanos

I got the battery replaced by a private since I had no warranty on it. I selected an AGM E65/66 battery and in the process they updated the software to register the battery. All in all, it cost me $300 to get everything done.

Lotus99

So every few weeks or so, I get a "Increased Battery Discharge!" warning on iDrive, and am told it's not a warranty-able item. Dealer told me over the phone it's a $500 charge to replace it!

So given its low frequency at this point, I'll wait it out and see, as I'm told batteries don't just die instantly. They usually give you some warning over time.

Though our driving habits have changed, and we're only driving the car every 3 to 5 days or so, and winter is now around the corner, so am wondering if I should be proactive about it...

Just out of curiosity I called a battery store, who told me they have a Group 49 battery for the car (though I forgot to ask him how many Cold Cranking Amps) which should fit for $150. That's not bad at all, even if I pay an hour's labour at the dealer after to get it registered.

Any idea how many CCA's are the OEM battery?

Vanos, how many CCA's was your AGM one? Interstate has a few listed on their site, ranging from $200 for a normal one with around 700 CCA's to $300 for an AGM with 900 CCA's.

vanos

I just saw your post, haven't been on in a while. I will look and get back to you (assuming I can find the info).