[Rewted]

Again this year when outside temprature reaches -20C (-4F) and my car isn't used for nearly 24 hours, clock resets and comfort access doesn't work.

This happened to me last year too, but the car sat for a longer period of time (2-3 days). I noticed this time around even the tire pressure warning (red) came on and had to be reset.

Now when I set the time, it still lost the next morning. Is this a good indicator for needing a new battery, or just needs to be driven longer to regain charge?

[morphius909]

Originally Posted by tyrewt

Again this year when outside temprature reaches -20C (-4F) and my car isn't used for nearly 24 hours, clock resets and comfort access doesn't work.

This happened to me last year too, but the car sat for a longer period of time (2-3 days). I noticed this time around even the tire pressure warning (red) came on and had to be reset.

Now when I set the time, it still lost the next morning. Is this a good indicator for needing a new battery, or just needs to be driven longer to regain charge?

Possibly. -20C is COLDDDDDDDD.

I would plug in a CTEk battery charger overnight in those temperatures. New or old battery your battery will love you.

Plus these cars are PIGs when it comes to battery recharging so you really need to drive it to charge. at -20C the battery initially won't even accept a charge from the alternator so your 30 minute drive barely begins to recharge the battery.

[Braumin]

This happened to me as well. It was outside at my in-laws at Christmas for 1 day at -30° C.

Started fine, but my clock was reset. I set it, and it lost time again. I figured no big deal, set it again and it reset again.

So I set it again, then I drove for 3 hours straight to come home. Parked it in my insulated garage, where it's barely below zero, and again my clock reset this morning.

I've booked it in, and I hope that they change my battery. I'm almost at the end of factory warranty.

[///M3NACE]

They don't cover batteries anyways...

[Braumin]

Batteries are covered under the original warranty. Apparently some dealerships are a**holes when it comes to covering them, but they are covered.

[Braumin]

Hopefully they don't argue with me too much. I mean, I drove the car for about 6 hours over three days, with a one day rest in the middle. I even locked the doors as they suggest to make sure all of the electronics are off (I was in the middle of nowhere so I wasn't too worried about theft). If that's not enough to keep the battery up, then it's obviously not any good.

I don't even think the battery is that bad, but the must have some pretty sensitive electronics. I mean, the car turned over fine, and started fine. If this was any other car I wouldn't worry about it but it's the car that's telling me to get it changed.

[rvdv]

Same thing happened to me, -15 degrees had to reset clock and lost all mpg settings, trip odo also reset. Car started fine normal cranking speed in cold so I doubt it is the battery. Any ideas? e90 328xi.

[fazman]

Originally Posted by Braumin

This happened to me as well. It was outside at my in-laws at Christmas for 1 day at -30° C.

Started fine, but my clock was reset. I set it, and it lost time again. I figured no big deal, set it again and it reset again.

So I set it again, then I drove for 3 hours straight to come home. Parked it in my insulated garage, where it's barely below zero, and again my clock reset this morning.

I've booked it in, and I hope that they change my battery. I'm almost at the end of factory warranty.

Your car has Alzheimer's, there is no cure

[VF154]

Mine is at the dealer for a battery issue, they think. Did your dash lights do any strange stuff like ABS,DTS and EBRAKE flashing on off. Also your gauges your sweeping from zero to full while drive?