Mavic pro BMS bypass

[onlyherefortheinfo]

Hello, I balanced one of my batteries to my mavic pro using a lipo cell balancer with no problems. I tried a new broken battery and did the same thing, unfortunately the battery seems bricked, and after fullly charging it and plugging it back in to the charger the #3 led flashes. By looking at the signal that the battery is giving me, it seems that there is an "over voltage". I'm not trusting that information, because when I check the cells, every one has from 4.25-4.32 each. When I check the voltages of the cells on the back of the bms board, I can only read one cell, but I can also read the main voltage of the battery.
It seems that the battery is bricked. I'm looking for some help, because I don't want to spend another 100$ for a new battery, if I can partially fix this one, or learn something at least.

 

[everBit]

I can only read one cell,

How you checked the cells before?

because when I check the cells, every one has from 4.25-4.32 each

 

[onlyherefortheinfo]

This way

 

[everBit]

Do you still have access to the connection board?
It's possible to measure cells voltages at those pcb, welding points are marked as B1-, B1+, ... B3-,B3+ accordingly. So it's easy to check.

 

[onlyherefortheinfo]

Do you still have access to the connection board?
It's possible to measure cells voltages at those pcb, welding points are marked as B1-, B1+, ... B3-,B3+ accordingly. So it's easy to check.

View attachment 107272
View attachment 107276

There is no problem with measuring them directly, there is no voltage on the board that I soldered the balance plugs to.

 

[Jetjohnc60]

Following your post with interest, have you found any way of resetting the board, i.e. clearing its memory so that it can start afresh?

 

[everBit]

Yes, bms memory could be cleared using Texas Insruments ev2300 programming board and accompanying software.

 

[Jetjohnc60]

It appears that the EV2300 costs more than a new battery.
I assume then there is no way of resetting the board by depowering the board manually?

 

[everBit]

Yes, power-on reset does not unlock the board as error flags are written directly to built-in EEPROM.
To avoid buying expensive ev2300 you could alternatively send your board to someone who have it like battery recelling workshops.

 

[Manpreet Singh Bhatia]

This guy is able to reset battery with nld software. It's russian but y can use the technique on any mavic I think. Last step is battery firmware update