BQ34Z100-G1: soc jump&passed charge jump

xiulan zhao

Part Number: BQ34Z100-G1
Other Parts Discussed in Thread: GPCRB

Hello,

During the discharge process, the PassedCharge() of the battery jumps, why is this? We recorded the value of CONTROL_STATUS synchronously, and found that CONTROL_STATUS also changed when jumping.

How can we avoid this problem? We have customized the chem id for the fuel gauge and optimized it with GPCRB. This leads to a jump in the SOC（from 14% to 0）. How to solve this problem?

When configuring the fuel gauge, the current is reduced by a factor of two. So when recording the data, we doubled the signal of I, PCHG,TRC&TFCC. So the range of these signals is different with others.In addition, we found that under the current load conditions in Figure 1, PCHG jump is inevitable.

6813.002U放电前.gg.csv 2工况放电-新测试柜1.0.3第2轮放电.xlsx

Sincerely,

Xiulan

over 2 years ago

0 Jose Couso over 2 years ago

TI__Mastermind 24956 points

Hello Xiulan,

This looks to me like a load mode or terminate voltage configuration issue. The gauge is overestimating Remaining Capacity.

We have an app note which discusses this phenomenon and provides possible solutions. Please see chapter three in the below app note.

https://www.ti.com/lit/an/slua948/slua948.pdf?ts=1663688060013&ref_url=https%253A%252F%252Fwww.ti.com%252Fproduct%252FBQ27426%253Futm_source%253Dgoogle%2526utm_medium%253Dcpc%2526utm_campaign%253Dapp-null-null-GPN_EN-cpc-pf-google-wwe%2526utm_content%253DBQ27426%2526ds_k%253DBQ27426%2526DCM%253Dyes%2526gclid%253DEAIaIQobChMI1MrRttij-gIVCBPUAR0IwQFgEAAYASAAEgLu2PD_BwE%2526gclsrc%253Daw.ds

Please let me know if you still have any questions.

Regards,
Jose Couso

0 xiulan zhao over 2 years ago in reply to Jose Couso

Prodigy 160 points

Hello Jose Couso,

I carefully read the documentation you provided. According to the experimental phenomenon, I think the SOC jump we encountered is caused by RUP_DIS.

In the subsequent discharge process, we found that RUP-DIS and the PassedCharge() jumps also appeared under different discharge conditions, which eventually led to inaccurate SOC. This problem occurs very frequently.RUP-DIS happen on every discharge cycle.

I suspect it is caused by the calculated negative resistance value. This means that our chem id information is wrong, however our chem id information is customized. Since we cannot see the ocv information inside the chem id, we cannot prove this speculation. Could you compare the test data to help us confirm whether it is caused by the inaccurate calculation of the negative resistance by ocv in the chem id? and how to solve this problem? Our chem ID is 5797.

Sincerely,

Xiulan

Sincerely,

Xiulan

0 Jose Couso over 2 years ago in reply to xiulan zhao

TI__Mastermind 24956 points

Hello Xiulan,

1- Usually when RUP_DIS is set when the wrong ChemID is being used. What was the percent of error ChemID 5797 had when you received the report from the GPC tool? Can you provide the report?

2- The gauge will only calculate the passed charge if there is a negative scale factor for Ra calculated, so I think the resistance data may not be correct.

Can you provide a regular log file with no customization? Please see an example below

While you start logging, can you also do an auto gg file export? This will export multiple gg files, that way we can keep track of resistance table and see if there's a negative resistance.

Regards,
Jose Couso

Power management

Power management forum

BQ34Z100-G1: soc jump&passed charge jump