XIAOMI m365 BMS Problem - Wrong Bank Voltages Shown

My problem was the following: two banks/cells were showing weird voltages - I measured them and the actual bank voltages were fine.

This ended up severely restricting the usable capacity of the battery pack: the erroneously low bank would cut the entire battery early, while the erroneously high reading bank would cut the pack early on the charge cycle.

[kiri]

Thank You! I had a problem that the BMS was dead, I charged all cells to the same capacity, welded the cells (it worked fine), and after a few days there was a problem with cell 9 and 10. Cell 9 was showing 4, 5V, and cell 10 was showing 3, 5V. After desoldering CF1 everything came back to normal.

[nikstoun]

Thanks for video, same problem i have too, B10 wrong voltage show bms ..blink red 4 times and not charge. But in my case i remove CF 1, its show difference when measure comprare to other capacitors. Now is back to charge :)

[steffenrbkhingelorentzcars]

Hey do you have a link to the diagram for the m365 bms?

[secureguard]

u couldn't have found a better time to clean up the screen, perfect spray for every BMS occasion, seeing better is more important than battery fire, great job

[MakerFabio]

Hi tha ms the the glod video
Which application is showing ea h cell voltage?

Do gou know which component is the regulator for the microcotroller, i have totally no action, no blinks

[Serwis_Elektroniki_]

Yesterday I repaired the battery with the same problem. Only today I started to google if this is a common problem and it turns out that not only I was doing it: D.

[cbrunnkvist]

Excellent, very good explanation of your troubleshooting process. One of my M365's suffered either a cell/group failure or a busted BMS, never figured out what to replace. Might give it another look under the magnifying cam ;-)

[pauliusnesakysiu]

Thank you for the advice. I had an 8-cell problem. I changed all capacitors to CF1-11. after the change, I drove 16 km with a 75% charged battery. Before replacing the capacitor +- 6km mileage and shows that the battery is discharged.

[KannyLive]

Is this problem after flashing the scooter?

[ruslansdakuzasvili]

I got problem too with charging, was unable to charge battery, but i was turned on but worked slow and all of the dots count from to one dot, after removing this capacitor, scooter not turning on anymore, battery woltage is ok, i charging battery with original scooter port, but without the bms, and it charging fine, i guess its Bms gone bad..

[lucacavallini]

If i understand, if i have pack not allineated, i must remove the corrispondent capacitor in that line Array?

[removecrypto]

Hi thanks for youre video. So you just renoved that cap?

[ZenyWorld]

Same here. 9 and 10 fucking banks. I see the Xiaomi should be fined for selling scooters with factory issues and no recalls. Xiaomi no more in my home.

[orkizozi]

great video. I had the same problem as in the video. turned out the problem was on one of the tiny resistors on the battery pack. I replaced it and problem solved. thanks

[kocakapo]

Ich was looking for a solution. I think i have the same issue. thank you for the video

[Edwintongol]

Hello darieee, have you ever know what is issue with the fast dried battery, after I ride 5 minutes the battery 8 %to 9 % less battery charged

[intuicio]

Hi! I have same problem, but at the cells 2 and 3… On cell 2 I have 3.55V and on cell 3 I have 4, 12V. All other cells have 3.8. I have alse measured everyone and all of them are same voltage. What will fix my problem? Same issue everyone? Thanks!

[stefanputureanu]

Thank you. Same problem here. Cells measuring good on multimeter (all at 3.65v) and BMS reported one cell empty - 3.1v and one overcharged - 4.25v. Measuring on the BQ inputs - voltages where right as the BMS reported.
First i have removed all caps from all BQ cell inputs (same problem) and then i removed the BQ chip (voltages got good on chip pads), then i have put the BQ chip back and removed all zenner diodes from the cell inputs - problem solved. My BMS had zenner diodes in parallel with the caps... on the multimeter the diodes measured good - 0.5v voltage drop - no leaks, but they influenced the chip somehow. BTW BQ chip is hard to measure without an oscilloscope... the inputs are oscillating between measurements of the cell (high impendance - normal voltage of the cell) and calibration of the cell (low impedance - voltage dropped). Now the battery is like new: it keeps a good charge and is charging normally. 👍

[sahiska]

me checking the electricity bill: please don’t be high
electricity bill: 02:17

[danielherda]

Do you know what specs are all CF1 - CF11 capacitors ?