• State TI Thinks Resolved
  • Locked Locked
  • Replies 1 reply
  • Answers 1 answer
  • Subscribers 62 subscribers
  • Views 248 views
  • Users 0 members are here
Support feedback
Options
Options
Similar topics

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

BQ34Z100-G1: Recommendations for test

Roger Hickey57
Prodigy 220 points
Part Number: BQ34Z100-G1
Other Parts Discussed in Thread: BQSTUDIO

Hello,

I am working with a system that uses a bq34z100-g1 fuel gauge chip to monitor the health and welfare of the batteries.

Do you have any recommendations on how to check the accuracy of the readings that I get from the bq34z100-G1 chip?

I am measuring the voltage, current, temperature, and SOC

I am mostly concerned about how to determine the accuracy of the SOC.

Thanks,

Roger

  • 0
    TI__Genius 14985 points
    Hi Roger,
    SOC is relative and actually is expected to change if the conditions of temperature or load changes, but if you keep the temperature and load constant during a discharge then it's simple to calculate the accuracy. You will need to capture a log file of the gauge registers, preferably once per second, starting from full while discharging to empty. Using bqStudio to capture the log file is the easiest way, but you can also use your host processor to read and store the data from the gauge. Import the log file into a spreadsheet. Then integrate the current to determine your total calcFCC (how much total capacity you got out from full to empty). Now in a new column you can back-calculate the calcRemCap for each point by subtracting the integrated current up to that point from calcFCC. Then calculate calcSOC = calcRemCap / calcFCC. The difference between true SOC and reported SOC can be your final column. Plot the voltage, reported SOC, and calculated SOC, as well as the difference.

    If your load or temperature changes significantly then of course the predictions in SOC before the change will have high "error" but this is not true error. The important thing is that the gauge converges fairly smoothly to empty.