BQ27542EVM: When the battery is discharged at a low temperature of -20℃, its charge drops abruptly from 20% to 0%.

Putong daz

Part Number: BQ27542EVM
Other Parts Discussed in Thread: GPCRB

Tool/software:

Hello, the 1S1P 5000mAh battery pack, incorporating the BQ27542 fuel gauge, was tested under various discharge conditions. The CHEM ID and GPCRB parameters were properly configured. The battery was discharged at 0.1C and 0.2C at 0°C, at 0.1C and 0.2C at -10°C, and at 0.2C at -20°C, with no anomalies observed. However, at -20°C and under a 0.1C discharge rate, a sudden voltage jump occurred at the terminal, causing the reported relative state of charge (RSOC) to drop abruptly from 20% to 0%. Could you please confirm whether this behavior is expected and advise on the potential causes? Kindly review the attached test data and GG file for further analysis. Thank you.

0081.BQ27542-1S1P 5000mAH.zip

6 days ago

0 Alan Frias 5 days ago

TI__Mastermind 25225 points

Hello,

This question has been assigned and will reviewed when possible, in the meantime please attach your .gg/.log associated with the project.

Thank you,
Alan

0 Jonny 5 days ago in reply to Alan Frias

TI__Mastermind 24741 points

Hello,

I recommend using the GPCRB tool to optimize your resistance values for low temperature.

Regards,

Jonny.

0 Putong daz 3 days ago in reply to Jonny

Prodigy 140 points

Hello Jonny,
I have successfully configured the GPCRB tool, and it operates normally at temperatures of -20°C, -10°C, and 0°C under a 0.2C condition. However, a 20% deviation was observed at -20°C under a 0.1C condition. I would like to confirm whether this deviation falls within the acceptable error range of the IC. Additionally, under low-temperature conditions (e.g., -20°C), is it possible for all current types to remain stable, or only specific types of current?

0 Jonny 3 days ago in reply to Putong daz

TI__Mastermind 24741 points

Hello,

I would expect the gauge to operate fine with the 0.1C discharge if 0.2C is fine.

Regards,

Jonny.

0 Putong daz 2 days ago in reply to Jonny

Prodigy 140 points

Hello Jonny,

now the 0.1C data is abnormal. What do you think is the reason for this? (Previously, GPCRB was conducted at -20℃/0.1C, and CHEM ID was also done with 0.1C data. May I ask how I need to improve? thank you

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BQ27542EVM: When the battery is discharged at a low temperature of -20℃, its charge drops abruptly from 20% to 0%.