BQ34Z100-G1: Known chemistry but GPC high deviation

Hi all,

I'am currently using a BQ34Z100 on a 1S8P LiFePo4 pack. 

I was quite satisfied with room temp performance, but observed SoC unreliability at low temp (SoC jump to 0% when 0°C reached)

After a bit of reading, I tried to run GPCRB. 

Calculation failed, with the below message :

Error: negative low temperature resistance observed, R=-16.1300087673119 usually caused by wrong chem ID selection

So I decided to proceed with GPC to confirm my chemID choice (I initially didn't because the cell manufacturer is listed in bqstudio chem id list and indicate us which chemID we should use).

Calculation works, but with high deviation to the closest chemID (which is not the expected one ;-)

Best chemical ID : 434 Best chemical ID max. deviation, % : 19.48

I tried with 2 different recorded cycles, but result is more of less the same. Could you please advice on what can be my next step, to select a proper chemID and get it optimized for low temp ?

Best regards

Benoît