Hi,
We need to find out the remaining capacity of the battery by communicating to the BQ2050 chip ( we know that its quite old chip, but the battery we are using is based on this).
We would like to know what is the correct way to find present remaining capacity by reading the registers of the BQ2050. Following is our understanding could you please help to find correct method.
After reading the data sheet we came to know about following parameters important for the SOC calculations.
- NAC: Nominal Available Charge
- CAC: Compensated Available Charge
- LMD: Last Measured Discharge
- DCR: Discharge Count Register
According to this CAC (16 bit) and NAC(8 bit) register gives battery capacity.
Which is the best an accurate formula we can use from these or there is any other suggestion to utilize them together to find the remaining SOC?
Understanding 1 (SOC based on CAC value)
Battery capacity in percentage = (CACH count*256 +CACL/CAC max)*100
Understanding 2 (SOC based on NAC value)
Battery capacity in percentage = (NACH count * 256 +NACL/CAC max)*100
Understanding 3 (SOC based on SAE value)
SAEH and SAEL to get the battery energy in mVh.
E(mWh) = (SAEH * 256 + SAEL) * (2.4 * SCALE * (RB1+RB2))/ RS *RB2.
where RB1, RB2 and RS are resistor values in ohms.
SCALE is the selected scale from Table 2. SAEH
and SAEL are digital values read via DQ.
Regards,
Bijesh V.M.
