BQ40Z50: Rapid RSOC Drop Issue with LiFePO4 Battery

choi soonho

Part Number: BQ40Z50
Other Parts Discussed in Thread: BQSTUDIO, GPCCHEM

Tool/software:

Hello,

I am developing a project using LiFePO4 batteries in a 4-series configuration. The battery specifications are JGNE’s JGPFR26650-3000mAh-3.2V, with a capacity of 3000mAh.

Usage Environment:

Always on standby after initial charge
Ambient temperature: around 40°C

Charging Conditions:

Charging voltage: 13.7V
Charging current: 800mA

Issue: After charging, the RSOC remains at 100%, but when the cell voltage drops below 3330mV, the RSOC drops rapidly. The actual battery capacity is over 99%.

Additional Information:

CHEM ID: 0x4124

I would appreciate any advice on this issue.

Thank you.

over 1 year ago

0 Anthony over 1 year ago

TI__Mastermind 29145 points

Hello,

If possible, can you please share the .gg file of the gauge settings and a bqStudio log file of the issue occurring so we can take a deeper look?

Regards,

Anthony

0 choi soonho over 1 year ago in reply to Anthony

Prodigy 70 points

PL4SM07_20240902_SET01_CHARGE_01_13p7V.log

PL4SM07_20240305_Serial0001.gg.csv

i attached gg file and log file.

thanks.

0 Anthony over 1 year ago in reply to choi soonho

TI__Mastermind 29145 points

Hello,

Thank you for sending those files, we will begin looking into them. Regarding the chemID in use, was the GPCCHEM tool used to find a match? If so, can you please send the report file given by the tool?

Regards,

Anthony

0 choi soonho over 1 year ago in reply to Anthony

Prodigy 70 points

Hello,

I was unable to find the CHEMID item using GPCCHEM. If necessary, I can work on it and send you the report file. However, it will take some time.

Thank you.

0 Anthony over 1 year ago in reply to choi soonho

TI__Mastermind 29145 points

Hello,

Understood, this will help us confirm if the chemID selection is causing this issue.

Regards,

Anthony

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BQ40Z50: Rapid RSOC Drop Issue with LiFePO4 Battery