BQ2060A: Calibration not being stored on chipset when using EV2200-60 and software

Hello Ashley,

That should not happen. Are you sure calibration is successful?

Do you calibrate at the minimum flash voltage?

The EV2200-60 software states calibration was successful.  When i reapply power, the correct voltage is displayed for a split second.  then it goes back to the uncalibrated voltage.

The voltage i am calibrating at is 3.8V.

I have never seen anything like it.

Hello Ashley,

Can you provide a screenshot. I have never seen this before.

Are you reading the parameters again in EVSW?

Precalibration

Post calibration before reboot.

Post calibration seconds after reboot.

post reboot after time elapsed.

Hello Ashley,

Did you make sure the EEPROM is programmed?

This looks to me as the EEPROM did not get programmed successfully. This device works with an external EEPROM, so please help customer check that the EEPROM is connected and programmed.

Kang,

If you would like, I can get the information off of the EEPROM by reading the EEProm values via the BQ software and see the offset value change from one value to another, and its corresponding hex value change as well.  The EEPROM is powered, and has the data stored as i can retrieve the data before calibration and after calibration.  The data is different after calibration, indicating the data was successfully stored on the EEPROM.  I have also checked that there is power to the EEPROM.  The screenshots also show that for a few seconds the data retrieved from the EEPROM is accurate, then changes to an odd value that isnt even similar to the value before calibration.  This tells me that the calibration offset that is set during calibration is carrying over correctly as well, just applying the offset to an incorrect value.

Hello Ashley,

Okay, let me check how to move forward on this debug.

Does this happen on just one unit or it happens on every unit? Seems like it should happen on every unit.

Kang Kang,

This happens on every unit.

Please let me know how we should proceed.

Thanks,

Ashley

Hello Ashley,

Can you check what Pack Config is set to?

Pack config is set to A4 before calibration.  

Hello Ashley,

I found some legacy documents that say this part is a ROM based gauge. It operates out of both RAM and EEPROM.

The bq2060A accesses the external EEPROM during a full reset and when storing historical data.

Are you able to program both the RAM and EEPROM with calibration data for it to persist?

Does the EEPROM need a higher voltage as well to program?

Kang Kang,

Ive tried calibrating the part as high as 4.2V and as low as 3.5V.  As stated on March 13, Ive been able to read the EEPROM values after calibration where the offset changes to reflect the calibration.  Ive also read the hex values after calibration and have seen that they change.  The reboot is indicative that the values have changed... it just doesnt stick and i am not sure why it defaults back to a previous reading, even though the offset is adjusted.

Thanks,

Ashley