BQ35100: BQ35100 Current Calibration

NAGA AMAM

Part Number: BQ35100
Other Parts Discussed in Thread: EV2400

Hi,

I am using BQ35100 EVM, EV2400, and BQ STUDIO combo to test the BQ35100 device features. Battery ChemID is set to 0x608 (TADIRAN, LiSocl2,19AH).

Also I am using two battery mode (J3 is set to 2-4s). Option-A register EXTVCELL bit is set. and I am applying 7.3V ( 2X3.6V) to BAT + and BAT- points.

It is reading Battery voltage accurately (BQ STUDIO ->Registers->Voltage) as 7.3V, but for current reading it is showing -16mA when 0mA is flowing between PACK+ and PACK- points.

I have calibrated the current reading by applying 50mA load between PACK+ and PACK- points, and so it read 50mA as -50mA, but 0mA current is showing as -16mA.

I am not really sure how to fix this issue, Please let me know how can I fix this.

Thanks,

Naga.

over 5 years ago

0 Jessica H. over 5 years ago

TI__Genius 11535 points

Hi Naga,

Please follow these steps below to calibrate your current. You should calibrate it at 0mA, not 50mA.

Best,

Jessica

0 NAGA AMAM over 5 years ago in reply to Jessica H.

Intellectual 270 points

Hi Jessica,

I am trying to calibrate CC offset value, I disconnected PACK- point and hit "Calibrate Gas Guage" button, but it is giving me error saying it sensed the current through sense resistor. I have even tried connecting PACK- point to BAT- , and verified the connections between PACK-, R18,R19,U1.10 etc using Multimeter, it looks good, but can't eliminate the error message. Please let me know if I am missing any.

Thanks,

Naga.

0 NAGA AMAM over 5 years ago in reply to NAGA AMAM

Intellectual 270 points

Hi Jessica,

Any updates here? Could you please try to run this CC calibration on BQ35100EVM and let me know your findings.

Thanks,

Naga.

0 Wyatt Keller over 5 years ago in reply to NAGA AMAM

TI__Guru** 107685 points

Hello Naga,

Can you share a screenshot of the error?

You should calibrate with higher current as well, 50mA is very low calibration current. After the 1A or 2A calibration then try the board offset.

Sincerely,

Wyatt Keller

0 NAGA AMAM over 5 years ago in reply to Wyatt Keller

Intellectual 270 points

I have tried 750mA calibration and then removed load between BAT+ and PACK- points, and tried to perform CC offset calibration ,

and I get the error as shown in the screen shot.

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BQ35100: BQ35100 Current Calibration