Other Parts Discussed in Thread: BQ34Z100, GPCRA0, BQ34110, BQ34110EVM-796, BQSTUDIO
I have a concept question about the BQ34Z100-G1 based on impedance track and use on NiMH battery.
If I have well understood, the BQ34Z100-G1 is based on OCV curve with impedance compensation to determine the state of charge of the battery.
I understand this work well on Li-Ion battery because the OCV curve versus SOC is independant from temperature and quite independant the fact the battery was charged or discharged before the OCV measurement.
But in Alcaline battery like NiMH, the OCV curve is very dependant from temperature and very dependant the fact the battery was charged or discharged before the OCV measurement.
See attached a curve that gives OCV versus SOC after charge and discharge.
OCV of NiMH batteries versus SOC after charge or discharge.zip
Could you explain how BQ34Z100-G1 can be accurate on NiMH battery?
The reason for this question is:
When I connect a BQ34Z100-G1 board on a Li-Ion battery, I have immediately a good SOC estimation.
But when I connect a BQ34Z100-G1 board on a NiMH battery, I have a false SOC estimation (for example SOC = 82% on an empty battery), I need to discharge again to battery until EDV to have SOC at 0%.
Thanks for your help
Best regards
Serge Maloizel