IBM ThinkPad battery refill

[kulik]

I changed Li-Ion cells in lapptop ThinkPad T22 battery, but there is no voltage on output of the battery gas-gage electronic. Before it was OK.
On battery side of gas-gage electronic is 11.4V.
During the refill process the gas-gage has been disconnected completely and later connected to cells again.
I have two explanations
1. the electronic inside disconnect the output
2. the electronic inside is damaged because I connected cells in correct polarity but random order (not ground first, max. plus second, ...).
There are 4 MOSFET driven by M61040FP and processor M37516.
Pls, do you have any advice?