[Patomtl]

Hello Everyone,

I just replaced the 12 volt Batt of my 2015 i3 Rex and now I'm not even able to put the car in Drive.

Would anyone have any idea on the issue, yes the high voltage was reconnected back.

I do have a check engine light turned on.
thank you all for the help,
Pato

[CnSky]

Did you code in the new battery? BMW batteries have to be coded in when changed.

[vreihen16]

Believe it or not, the i3 will operate normally after a battery swap even without registering the replacement. They say that registering it changes the charging profile to prolong life, but given the ~3-4 year lifetime even when registered I have my doubts that the registration does anything more on an i3 than write an entry into the on-board maintenance log for the dealer to reference next time it is connected to the BMW mothership.

I don't remember disconnecting the high voltage when I changed my 12V aux battery. I did register it a few days after the change though, but only because I had a compatible Bluetooth OBD-II dongle for another vehicle.....

[ovesund]

There is no need to disconnect the HV cables when replacing the 12v battery.
It's just a pain to access the battery.
I didn't code in the new battery, and even the BMW dealer said that it was not all that necessary on the i3. The only odd thing is that I guess the car got into some kind of learning mode for the next 13 hours or so.
I could see that the wall box switched on and off several times overnight. at first maybe twice an hour and then it turned on more seldom and for shorter periods before it finally stopped.
I also got the warning regarding high power consumption when going for a drive after replacing the battery.

Everything went away the next day and it has worked flawlessly since then even with the daily pre-conditioning during winter.

[freshxdough]

Originally Posted by Patomtl

Hello Everyone,

I just replaced the 12 volt Batt of my 2015 i3 Rex and now I'm not even able to put the car in Drive.

Would anyone have any idea on the issue, yes the high voltage was reconnected back.

I do have a check engine light turned on.
thank you all for the help,
Pato

Clear faults. Also you’re supposed to disconnect HV before you replace 12v battery or you can damage switch contactors.

[freshxdough]

Originally Posted by ovesund

There is no need to disconnect the HV cables when replacing the 12v battery.
It's just a pain to access the battery.
I didn't code in the new battery, and even the BMW dealer said that it was not all that necessary on the i3. The only odd thing is that I guess the car got into some kind of learning mode for the next 13 hours or so.
I could see that the wall box switched on and off several times overnight. at first maybe twice an hour and then it turned on more seldom and for shorter periods before it finally stopped.
I also got the warning regarding high power consumption when going for a drive after replacing the battery.

Everything went away the next day and it has worked flawlessly since then even with the daily pre-conditioning during winter.

There is absolutely a need to disconnect HV when replacing 12v battery properly.

[MagicCarpet]

Disconnecting HV is a precaution to prevent the 12V inverter coming on in attempt to charge the 12V battery while you are changing it. HV cables are not disconnected its done by pulling the "disconnect" link under the hood.

When attempting this step, I found it impossible to unlock the HV disable link, mine is the later green connector 2017 year on. rather than destroy this link, I waited for the HV to go to sleep then put another battery across the 12V terminals while undoing, removing old 12V and connecting the replacement.

Did not recode for different batt as its essentially identical. No issues with the car. Old batt 7 years old and returned a capacity test about 80% spec this is the best condition "old" batt I've ever replaced, I only thought it was sagging after a few days idle but never had any issues.