"Smart" BMS with OZ8920-TN microchip

[Joost]

Hello everyone,

A week ago I bought some "defect" batteries from a dealer.
Now I'm opening all the packs and measured one by one group. One pack has a fault group that not will wake up.
The batterie packs are oke, but wen I want to charge them it stops after a half hour.
After a inspection I discover two O2 Microchip type 8920-TN.

My question is is there a reset possible without te reprogramming it?
And if I need to reprogramming it can I use my Atmel AVR Dragon board?
The BMS has two "jp" connectors with 4pins!


O there is no B+ on the board as I wrote on the topic Smart BMS OZ890.

Anyone who know more?

 

[dustNbone]

If it has no B+ connection (many don't) then pulling off the balance lead plug (small wires) will cut power to it as it's drawing it's supply power from those. That might reset it, if it's not programmable.

 

[Joost]

Thank you for replying.

Ic don it already but no effect.

 

[Joost]

Heer are photos

 

[Joost]

Strange!!!

I've opened the battery pack and discovered that it is not a 16s is but 13s!!
Wtf is the reason to use a '16s' bms on 13s?? Could it be to speed up the bleeding process?

Someone know more?

 

[Matador]

Strange!!!

I've opened the battery pack and discovered that it is not a 16s is but 13s!!
Wtf is the reason to use a '16s' bms on 13s?? Could it be to speed up the bleeding process?

Someone know more?

Maybe only 13 channels on the 16 available are used ? Heard sometimes you have to tie the unused chanels togoether for it to work, but I'm no expert... Problebly BMS model/type specific...

 

[Joost]

Now I got response from O2 Micochip!

OZ8920 is standard programmed for LiFePo4!!
It could be the problem...
Now I need a programmer but this cost $200,-