• State TI Thinks Resolved
  • Locked Locked
  • Replies 3 replies
  • Answers 2 answers
  • Subscribers 63 subscribers
  • Views 699 views
  • Users 0 members are here
Support feedback
Options
Options
Related

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.

BQ27220: Issues with BQ27220 battery % reading

Poh Kok Keng
Genius 5512 points
Part Number: BQ27220
Other Parts Discussed in Thread: GPCCEDV

Dear Sir/Madam,

 

We are having issues with BQ27220 battery % reading. We find that most units the battery % randomly drops. Attached is log file for 13hrs of battery discharge from full capacity. Initial capacity is 13072mAh.

 

Column B to O are registers from BQ27220.

 

At time T=521.8minutes the battery percentage (column D) drops from 27 % to 7%. We observe similar behaviour on all units.  The FCC also suddenly reduces from 13072 to 12944.

Can you pls review and give us some hint on what we are doing wrong? I suspect we may not be initializing some registers.

 

Best regards,

KPKBatteryGaugeLog_Remote_discharge_debug.xlsx

  • 0
    TI__Guru* 76230 points

    Hi Kpk

    This device is a CEDV gauge, meaning that FCC is learnt at the EDV SOC thresholds which are 7%, 3% and 0%- hence the drop you see to 7%. In order to have the gauge have good accuracy, you need to configure the gauge properly using our online  gpccedv tool. Was this done?

    Also, your host needs to have Non volatile memory where you store the gauge updated data memory parameters  in case power gets cut off from the gauge and the default settings of the gauge gets restored.

    thanks

    Onyx

  • 0 in reply to Onyx Ahiakwo
    Genius 5512 points

    Hi Onyx,

    End customer do not want to have an external Non-volatile memory to add-on cost to their design, so they want to use MCU to write the registers configuration to the gauge at every power cycle. 

    They would like to know which parameter in the gauge register actualy contributing to this sudden drop in to 7%. Will you be able to advice? what is the way we cn adjust it to 0%?

    We have tried before to do the battery training, but i will said it is a pain and difficult task to complete.

    Best regards,Kpk

  • 0 in reply to Poh Kok Keng
    TI__Guru* 76230 points

    HI Kpk

    Without configuring the battery correctly following the instrcutions from GPCCEDV, you will not be able to get the gauge to function correctly. It is not just one parameter than needs to be configured.

    thanks

    Onyx