Xiaomi Roidmi EVE Pro battery died!

[CidiRome]

Hi there.

I hope one of you may be able to help me.

My Xiaomi Roidmi EVE Pro battery died.
I disassembled the battery and tested the cells to find 2 dead and other 2 almost dead.
I then dug some batteries from my notebook battery bucket and recovered 8 cells to rebuild the battery.
Yet I can't get the BMS to start working again: the output is 0 Volts and it won't charge either.
Did not try to put it in the robot yet, but I don't think the robot will reset the BMS...
The current cell balance is good with a total voltage around 14.5V.
Any Ideas?

[sam_sam_sam]

Re: Xiaomi Roidmi EVE Pro battery died!

Try this do you have an adjustable power supply if so try slow bringing of the voltage from around 0 volts to around 10 volts or so and then see if it will charge you might have to limit the current because some BMS protection board are weird like that I have a few of them that if you go over 2 amps they play dead but if you limit the current to 500 to 1000 milliamperes they work fine

The other possibility is that the voltage is a little to high and the BMS protection board is locked out

Or you need the third wire to activate the BMS protection board although I have not run across one yet like that

If that does not work then maybe that is why the battery are dead the original ones and the BMS protection bad

[CidiRome]

Re: Xiaomi Roidmi EVE Pro battery died!

Hello.

Thank you for trying to help.
It seems that the issue is this component that Sorin is referring to in this Video:
https://www.youtube.com/watch?v=zVGD...ygUFZDZzYzQ%3D

I will try to dig one from the battery bucket.

Cheers.

[sam_sam_sam]

Re: Xiaomi Roidmi EVE Pro battery died!

https://www.youtube.com/watch?v=zVGD...ygUFZDZzYzQ%3D

Thank you for sharing this information and the link to it this will help me a lot with attempting to repair BMS protection board issues

Could you please show a picture of where this fuse is located on your BMS protection board

[eccerr0r]

Re: Xiaomi Roidmi EVE Pro battery died!

deleted, I posted to wrong thread

[CidiRome]

Re: Xiaomi Roidmi EVE Pro battery died!

Hello.

Please check the attached picture.

Hope it helps someone else.

Cheers.

[sam_sam_sam]

Re: Xiaomi Roidmi EVE Pro battery died!

Hello.

Please check the attached picture.

Hope it helps someone else.

Cheers.

Did you try to temporarily bypass the fuse and see if it comes back to life and functions correctly or not

I would not recommend leaving with out the fuse if you plan on using this BMS protection board but just for testing purposes

[CidiRome]

Re: Xiaomi Roidmi EVE Pro battery died!

Hello.

I know that it will work if I bypass it, because I get voltage in the cable if I short it with the tweezers.

I ordered it to replace.

Cheers.