Hi,
we consider to utilize the BQ34110 in our application. It'll gauge NiMH cells (e.g. 6 series VHT D cells from ARTS).
Below, you'll find a line graph with measured data from a charge of a ARTS 6 series VHT DL battery with 6450 mAh capacity.
Charging current was constantly at 460 mA while being exposed to room temperature.
The sample interval is four seconds and the whole procedure took approx. 23 hours.
"Temperature" is derived from a NTC thermistor attached to the battery.
"IntTemp" is derived from the internal temperature sensor of the BQ34110 and shall be considered as the ambient temperature.
The "Technical Reference Manual" SLUUBF7A states, that one can utilize only the delta voltage or delta temperature method when gauging NiMH cells.
Because of the low charge current the delta voltage method becomes void, doesn't it?
The final product is deployed offshore (i.e. harsh environment conditions).
Therefore, it can be reasonably assumed that the ambient temperature is not constant while the battery is charged!
Is the BQ34110 able to reliably detect the charge termination under these conditions?
Thanks,
Christian
