Hi there,
We're using the BQ27541-v200 fuel gauge in our battery pack with an external thermistor populated as well.
(a) Without any calibration (i.e. the internal & external offset values are "0"), the temperature reading of the external thermistor (1% tolerance part) is always greater than the internal temperature sensor. Is there a proper explanation for this phenomenon?
(b) In TI's slua504a (Going to production with the bq2754x) under Temperature Calibration (pg. 3), the instruction is "Select the Temperature Calibration checkbox and have Int. Sensor unchecked and Ext. Sensor 1 checked". What is the reason for unchecking the Int. Sensor? Is it not recommended to use the Int. Sensor as it is embedded in the IC and thus would not provide a true reading of the battery cell temperature?
Thanks,
Chin Keong