Page 1 of 1

DIY battery replacement e90

Posted: Tue Jan 19, 2016 9:21 pm
by nj325ci
I can't believe I'm actually asking such a basic question but is it true that you can't just replace a battery in recent model BMWs without having to do a reset procedure requiring the proper scan tool? What procedure does the dealer follow that can't be replicated at home? I'm not trying to take short cuts but my car has enough juice to power lights etc but not turn over and it would be less of a hassle to pick the new battery up and do the swap in my driveway than to charge the current battery and bring the car to the dealer.

Thanks, Bill

Re: DIY battery replacement e90

Posted: Tue Jan 19, 2016 10:34 pm
by afadeev
nj325ci wrote:I can't believe I'm actually asking such a basic question but is it true that you can't just replace a battery in recent model BMWs without having to do a reset procedure requiring the proper scan tool? What procedure does the dealer follow that can't be replicated at home? I'm not trying to take short cuts but my car has enough juice to power lights etc but not turn over and it would be less of a hassle to pick the new battery up and do the swap in my driveway than to charge the current battery and bring the car to the dealer.

Thanks, Bill
Bill,
Modern BMWs and MINIs have added adjustable charging algorithms to the alternator software. In theory, if your old battery was extremely weak for a long time, the alternator could have been set to charge at an aggressive rate to keep it going. And if you put in a new battery without resetting alternator software settings, it may attempt to over-charge it.
http://atlanticmotorcar.com/tech-tip-bm ... acement-2/

Done competently, "battery registration" takes 5 minutes.
If you take it to a dealer, they will charge you for at least 1 hour of labor, bringing the total to $400+ (including over-priced OEM battery).

In real world, most people I know who DIY their cars just throw in a new Autozone / PepBoys / DieHard / etc / battery of equal or higher rating, and report zero problems.
Just make sure it's the same lead-acid (or AGM) battery that came out.

YMMV,
All generic disclaimers apply.
Do not eat, lick, or swallow. Not a toy.
Do not remove this disclaimer under penalty of law.
https://sites.google.com/site/beecherbo ... isclaimers

a

Re: DIY battery replacement e90

Posted: Thu Jan 21, 2016 12:41 am
by BJerolimic
Bill if you get the right battery (correct amp hours, not just the same group type battery) I can register the new battery with my Carly adapter and BMWhat app. I purchased both as I had to swap in new battery on my wife's "new" e70 X5

Re: DIY battery replacement e90

Posted: Fri Jan 22, 2016 2:28 pm
by nj325ci
Thanks very much, I'll defintely PM you when I get the battery. It's holding a charge from day to day so I can get the battery and work around your schedule. Since I last saw you my work location has moved to Morris County so I can easily catch up with you.

And BTW congratulations on the additions to your growing family, your daughter and your e70!!! (saw that in another post)

Thanks again, Bill

Re: DIY battery replacement e90

Posted: Tue Jan 26, 2016 7:25 am
by BJerolimic
thanks!


btw I found the best deal was at Batteries Plus in Whippany, at least for my e70 (may be different battery than your e90 and again you need to find the right or closest AH battery to what is currently in the car), more details on batteries for newer BMWs and some price shopping + warranty comparison:

http://www.xoutpost.com/1057230-post67.html