BMW MINI E...ev battery too low to charge

[BHP4EVER]

Hi Guys.

I have a 2020 mini e that has had body damage...due to the car being repaired and not charged the EV battery is now flat and wont charge from the charging socket.

So i have this to strip and charge up the battery.

Can anyone help me with any info please on how to charge these cells up.

I understand i need to reverse engineer the bms and find out all the cell wires...but any info would be appreciatted..

At this moment i have the battery off the vehicle and ive opened the battery case..

Thanks in advance.

[Aragorn]

I've heard anecdotally that some BMW systems have a "lockout" in the BMS. If the battery is discharged too low, or the vehicle is crashed, the BMS can go into a state where it will essentially brick itself. I dont know the specifics though. But if that is the issue, you may find that manually charging the battery wont actually help you, unless you can reset the BMS lock.

Given you have the battery out, first step is to measure the cell voltages and see what they are actually doing. If they are extremely low it might be unsafe to attempt to charge it. Even measuring at module level will give you an idea if its okay. You shouldnt need to reverse engineer anything at this point, your just probing voltages.

If the voltages look sane (not too low and even accross all modules), you can likely just charge each module with a bench psu with a sensible current limit. You may also find at this point that the voltages are all totally fine, and the BMS has locked the pack.

[BHP4EVER]

Thank you Aragorn for the reply...the vehicle has been on diagnostics and that was showing low cell voltages.

Also just to clarify.There are no crash damage data codes stored in the car at all...The car had very little damage to the osr outer panel and after the crash vehicle was still driving.
Vehicle has been repaird with a new outer quarter panel and there was no damage to the charging socket,
BUT i have a question...The charging socket has no locking device in it all all...ive done some research cant find the answer....does this socked have a locking device on it...im 100% sure it should.As if you parked the vehicle up to charge while you went shopping...someone can remove the charging plug.

[BHP4EVER]

So i have one of the seven battery packs...Ive removed the covers to find the cells...And i can now charge the cells up.
all cells are reading 2.2v.....Im charging the cells up seperatly and im charging to 3.2v.
Is this voltage ok....Im asuming 3.2v on each cell should be enough to bring the battery back to life.

[ted.walsh]

Hi Guys.

I have a 2020 mini e that has had body damage...due to the car being repaired and not charged the EV battery is now flat and wont charge from the charging socket.

So i have this to strip and charge up the battery.

Can anyone help me with any info please on how to charge these cells up.

I understand i need to reverse engineer the bms and find out all the cell wires...but any info would be appreciatted..

At this moment i have the battery off the vehicle and ive opened the battery case..

Thanks in advance.

I use the similar 16 cell Li-Ion BMW bricks in my project, (as 6S-2P) (not sure if your e is a hybrid or not?) I dont have any sophisticated charging or balancing going on yet so just charge them us using a 15a li-Ion 67.2v charger and croc clips directly onto the terminals. seems to work fine, I monitor the cell voltages using one of Tom's citini.co.uk BMS managers - seems to work ok I just need to make it more sophisticated...I dare say someone with think Im a madman so use this info at your own risk

[BHP4EVER]

Hi
just a update...after weeks of charging the cells up,then a week on holiday.Ive finally got round to refitting the battery pack...all connectted....but im getting errors in the SME module.
i have error codes for the contactors.
errors codes regarding temp sensor coolant temp..i asume thats because there is no coolant in the system.
error codes aswell for all cell supervision modules..

"HIGH VOLTAGE BATTERY UNIT-NO COMMUNICATION WITH CELL SUPERVISION CIRCUITS 1-12"

I have taken so many photos before i stripped this down..ive checked my photos and everything is connected..

Can anyone help me with this please.

[ted.walsh]

Hum, sorta sounds like there may be a problem with the management controller module? all the bits get routed by that device. if it has an internal voltage supply problem it could give you issues like you describe possibly? I dont use that particular unit and my s-box control is all done direct from the zombie. debugging that sorta stuff can take ages...
I picked up a great value 5 brick mini hybrid pack the other day, the breakers couldn't wait to sell it on and im not surprised cos when I tested it there was an S-Box fault caused by a fried pre-charge resistor so useless to anyone not in the know. clearly a warranty swap out that had made it back onto the market...

[BHP4EVER]

Hum, sorta sounds like there may be a problem with the management controller module? all the bits get routed by that device. if it has an internal voltage supply problem it could give you issues like you describe possibly? I dont use that particular unit and my s-box control is all done direct from the zombie. debugging that sorta stuff can take ages...
I picked up a great value 5 brick mini hybrid pack the other day, the breakers couldn't wait to sell it on and im not surprised cos when I tested it there was an S-Box fault caused by a fried pre-charge resistor so useless to anyone not in the know. clearly a warranty swap out that had made it back onto the market...

thanks for the reply.
It sounds like you have dropped on a bargain with the hybrid pack.
Can i ask...would you sell some of the wiring and the main module...i would like this to try with arduino.