Other Parts Discussed in Thread: BQ27441-G1, , BQSTUDIO, GPCCHEM, BQ27427, BQ27426
Hello,
We are using BQ27441EVM-G1A to Monitor the SoC (State of Charge) and Voltage of 900 mAh battery, based on the battery specifications and the quick start guide of BQ27441-G1 we are configuring these values.
Design capacity : 900 mAh
Design Energy : Design capacity * 3.7
Tapper Current : 50 mA
Tapper Rate : 10 * ( Design capacity / Tapper Current )
Terminate Voltage : 2700 mV
We are not using bqstudio for this configuration, we are writing these values through I2C interface. Below we have listed the battery specification on which we have done the testing. It is a LiPo battery.
Battery Chemistry : LiPo
Nominal Voltage : 3.7 volt
Design Capacity : 900 mAh
Max. Charge Current : 450mA
Standard Charge Current : 180mA
Discharge Current : 900mA
Standard Discharge Current : 450mA
we are using the sparkfun's library to configure the BQ27441EVM-G1A board and to read battery related parameters. We are reading the battery voltage, SoC, remaining charge capacity, full charge capacity, and current value. During our testing we observed that the SoC and remaining charge capacity values are not accurate.
When battery is first inserted the SoC value is 20% and battery voltage is 3.7 volts, the voltage is accurate but the SoC is not. the SoC is corrected only after charging the battery. If we remove the battery and reinsert the fully charged battery then read SoC value is 53% which is again not accurate.
So, can you please tell us if we are missing something or there is need for this chip to go through a learning cycle for accuracy?