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eeyore8 12-26-2016 04:18 PM

2012 Battery Replacement
I plan to replace the original battery in my 2012 35i soon. I have been reading battery threads and have two questions:

1) When I disconnect my current battery, what car settings will I lose (radio, seat memory, etc.)?

2) Will connecting a Ctek charger to the under hood attach points before disconnecting old battery prevent settings from being lost? Or should I connect Ctek directly to battery cables?

I plan to fully charge the new battery using a Ctek after installing then register it using iCarly.

Anything else I should do or know about?

Doug Huffman 12-26-2016 05:40 PM

2) Connect it under the hood and you should lose nothing. Be careful, the battery terminals that you will be working with will be hot with all the current that the CTEK can provide.

One needs to keep the work area as simple as possible.

Fully charge the battery with the CTEK on the bench before installation.

A PIA job from early in my career was removing electric plant control panel meters for calibration, that had to be done 450 VAC hot. We built a rubber room with only a hole in the curtain to work on the particular meter, but it was really cramped. Once I was 'safety' while another guy was working, and he yipped and jumped a half dozen times before we could get him out. 450 VAC hurts.

DieselDonkey 12-26-2016 05:43 PM

I didn't lose much when I changed mine.
Just turned wheel lock to lock to reset a message.
Easy peasy

Gold323Ci 12-27-2016 08:17 AM

When you replaced your battery, how did you reprogram it? Did you have it done or do it yourself.

I'm not opposed to doing it myself but not sure when it makes financial sense. I have an Ipad and a laptop but the laptop belongs to my employer and it is locked to adding new software.


eeyore8 12-30-2016 11:01 AM

Replaced battery today and registered with carly. Hooked car up to a Ctek while changing and only lost clock settings. 4X4 warning light and message came on after starting car with new battery and turning steering wheel lock to lock cleared that. Total job took 30 min. Thanks for the advice. And battery cost $189.

mkal 12-30-2016 11:18 AM

Was CTEK even relevant here as an auxilary source? According to manual, minimum voltage for it to charge a battery is 2 volts, so if the battery was disconnected, CTEK stopped charging and it would explain why you've lost clock settings.

Milliwatt Rob 12-30-2016 12:16 PM

Rather than a CTEK, I think you would do better to use one of the battery jumper packs as a voltage source when changing your battery.

mkal 12-30-2016 12:20 PM


Originally Posted by Milliwatt Rob (Post 9981212)
Rather than a CTEK, I think you would do better to use one of the battery jumper packs as a voltage source when changing your battery.

Agree. That or any other vehicle with 12V battery.

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