SLUAAL7 September   2022 BQ35100

 

  1.   Abstract
  2.   Trademarks
  3. 1Introduction
  4. 2EVM and System Setup
  5. 3Enabling EOS Mode
    1. 3.1 Steps for Enabling EOS Mode
  6. 4I2C Communication Between the Microcontroller and the BQ35100 EVM
  7. 5Testing Procedure
  8. 6EOS Data Example
  9. 7Final Configuration of the BQ35100 Data
  10. 8Conclusion
  11. 9References

5 Testing Procedure

While in EOS mode, the gauge needs to be enabled before any major discharge of the battery occurs. For this test, the MCU gathers impedance data and writes the data to a data memory device. The testing procedure consists of the following steps:

  1. Wake up the gauge before any major discharge using the GE pin
  2. Send the GAUGE_START command
  3. Send the GAUGE_STOP command after the major discharge
  4. Wait for the G_DONE bit to be set to one
  5. Read the scaled resistance and measured impedance from the gauge
  6. Save the scaled resistance and measured impedance to a data memory device
  7. Put the gauge back to sleep using the GE pin
Note:

The G_DONE bit is found in bit 6 if the CONTROL_STATUS command

For the gauge to take an accurate measurement of the voltage and current for estimating the resistance of the cell, the pulsed load must be at least 100-ms long and cause a 100-mV drop of the battery voltage. This constitutes the minimum requirement for a major discharge.

It is common for end equipment to use separate resistors from the expected load burst, which is typically RF dynamic load, to provide consistent current bursts for the gauge to learn the resistance. The gauge thrives on consistency of the measurements and does not require significant drain on the battery to perform the learning load burst.