[GenesisKnight]

Had an odd occurrence last week. Of course, it was on a day I'd promised my partner that I'd be home on time for dinner...

GF wasn't happy when I sent a picture showing a Power Supply issue.

When I'd pulled out of my office parking lot, I had a quick message noting that there was apparently additional power required for the steering system...but it went off right away.

500m later, the CEL comes on and a message saying: "Check Control - Power Supply". Telling me to pull over and that the battery can't be charged. Called Roadside, they downloaded the diagnostics and said it looked like the alternator wasn't charging the battery. They were great to deal with...dispatched a tow truck and an uber.

Too bad the tow truck took 3 hours!

The Service Department called first thing the next morning...which was awesome...but left a message saying they were investigating the Drivetrain...not the power system. Thankfully I was able to get a hold of them and put them on the right track.

From what I understand, there were under-volt errors being tossed by the battery (48v) and stopped the system from charging. They reinstalled some controller software(??) and got it running by end of day under warranty (THANKFULLY)

Anyone else have issues along these lines? They didn't tell me what might have caused it at all...

[G22b58]

I check the charging of the 48V system in the iDrive Energy Flow display. From low levels it is also possible to force charging, up to at least 3 bars, by the engine by in Neutral increase the engine RPM to around 3000.

I also, from time to time, check the charge level of the 12V battery, using BimmerLink. BimmerLink can also display the status of the 48V.

Mine is also a 2021 model and I wonder about the design life of the MHEV battery. It lives a hard life constantly charging/discharging.

[gnyce]

https://g20.bimmerpost.com/forums/sh....php?t=2152373

[GenesisKnight]

Originally Posted by G22b58

I check the charging of the 48V system in the iDrive Energy Flow display. From low levels it is also possible to force charging, up to at least 3 bars, by the engine by in Neutral increase the engine RPM to around 3000.

I also, from time to time, check the charge level of the 12V battery, using BimmerLink. BimmerLink can also display the status of the 48V.

Mine is also a 2021 model and I wonder about the design life of the MHEV battery. It lives a hard life constantly charging/discharging.

I'd literally just had the car in for its regular service two days prior, so I was a little miffed at the dealership to say the least.
Not a single squeak of anything at all to suggest anything was wrong prior.