BQ40Z50-R2: Learning Cycle Issue

Hi TI Team,

When we used the BQ40Z50-R2 gas gauge to do the Learning cycle test, we encountered a issue. The Learning cycle had been successful, but the obtained battery capacity was incorrect. Please help to check the problem. Thanks! The detail issue information is described as follows:
1. Our actual battery capacity is 26127mAh, but the value of register FullChargeCapacity() is only 19839mAh, which is very different from the actual capacity.
2. We used the existing CHEMID in TI's CHEMID library to carry out the Learning cycle. The CHEMID of our own battery is still under TI certification, and Marco from TI's US team is helping to follow up this test.
3. gg file is attached for your review since the success of the Learning cycle.

TI Returned CHEMID Result.rarTo Match chemical ID test data.rarLearning Cycle.gg.csv

Alice：

您好， 已经收到了您的案例，调查需要些时间，感谢您的耐心等待。

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Lydia：

Hi,

Can you please confirm how many cells are in use currently? Also, can you please share a log file of the learning cycle so we can look into it?

Regards,

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Rain Cao：

Hi Lydia,

Thanks for your feedback.

We are use 1s4p cells in the pack. We did not save the log during the test, we have arranged to test again, and the log will be provided after the test is completed. In the meantime, can you give us some ideas on how to solve this problem? Thanks again for your help!

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Lydia：

Hello,

Without seeing a .log file of discharge and charge cycle is it is really hard to pinpoint a solution without it being a shot in the dark. The least likely but still a good place to start is your chemID, could you attached your GPCCHEM report to verified that your chemID option are below 3%. The best suggestion would be to look at section 6.5 of the Technical Reference Manual to see how each part plays within FCC. The other possible issues that the FCC could stem from is if your team manipulated/ not following the procedure for the learning cycle.

Technical Reference Manual:https://www.ti.com/lit/ug/sluubk0b/sluubk0b.pdf?ts=1744648456038&ref_url=https%253A%252F%252Fwww.ti.com%252Fproduct%252FBQ40Z50-R2

BQ40Z50 Setup and Going to Production:https://www.ti.com/video/5833131913001

*Qmax is created after learning cycle, Ra tables are based on chemID

Thank you,