BMW 7 F04 2011 ActiveHybrid

[Diablo91]

Hello friends. There is a car being repaired, a 2011 BMW F04 ActiveHybrid. It contains errors in the SME block. As it all happened, the main 12V battery was discharged, they tried to start the car on a discharged battery and errors appeared on the hybrid battery. I will attach the errors below in the screenshot. We tried charging the hybrid battery using a powerful charger, but the battery still does not want to charge. How do I understand that the hybrid battery has discharged to a critical level and now it cannot be repaired without opening the battery? Does anyone have experience repairing a hybrid battery?

[Evergreen]

Hey my friend, unfortunately when the 12 volt discharges it will then begin to discharge the hybrid battery.

From SI B61 18 08:

Battery Maintenance Requirements: Battery Care
New information provided by this revision is preceded by this symbol .


This Service Information bulletin supersedes SI B61 18 08 dated November 2015.
MODEL
All (new vehicles in BMW center inventory)
SITUATION
Proper battery maintenance is vital when BMW vehicles are in your center’s inventory. Allowing a vehicle’s battery voltage to drop below 12.0 volts (12.0V) permanently reduces the battery life expectancy and can lead to premature failure of the battery. For vehicles, equipped with a high-voltage battery (hybrid/electric vehicles), failure to properly maintain this battery may lead to a greatly discharged HV battery, requiring replacement.
We provide a flexible battery maintenance system every BMW center can use to meet their particular needs. This bulletin explains the Battery Charging Calendar (see attachment), charging system categories and a simplified tool and battery voltage checking procedure below.

IF you're able to open up the pack and get behind the HV contactors, you can recharge the battery to a sufficient SOC, however, if you have not had experience manually charging large lithium-ion batteries I greatly recommend you research the process extensively to prevent cell structure stress and fires. The Autel MaxiSys Ultra EV package will assist in connecting to the BMS while the battery is charging (out of the vehicle) by supplying 12 volts and direct pinning to the BMS so you can safely watch all the cells charge individually. The two biggest issues with all hybrid and EV batteries typically involves loss of isolation, and an unbalancing of cells which is what your faults are showing currently. If you're able to wipe the BMS after charging the HV battery you should be able to start the vehicle. Any data PID detailing why the HV contactors are open will be where you want to focus. As always, use fresh 12 volt batteries and register them to the vehicle.

Good luck, andI know this post is old, but if you get stuck feel free to reply!