BQ27427: Why does the battery level stop at 99% during charging?

? ??

Part Number: BQ27427
Other Parts Discussed in Thread: EV2400

Tool/software:

As I asked, I directly connected my PCB with EV2400. There is only one I2C device, BQ27427, on this PCB. BQ studio software can read the relevant information normally, as shown in the picture. The battery information has been set, but it keeps stopping at 99% during charging. The FC flag cannot be set and self-learning cannot be completed. May I ask where this is not configured? At the end of the document, I have attached the exported GG file.

Here is the configuration file:

5460.myConfig.gg.csv

7 months ago

0 Anthony 7 months ago

TI__Mastermind 28470 points

Hello,

It seems like in your configuration the SOCHold99 is set, is there any difference if this is disabled?

Regards,

Anthony

0 ? ?? 7 months ago in reply to Anthony

Prodigy 20 points

Hello,Anthony
The configuration of this register is default. According to the manual's description of opconfigC, if the FC bit is not set, the battery level will stop at 99%. Therefore, the most critical question should be: why cannot the FC bit be set?

Regards

0 ? ?? 7 months ago in reply to Anthony

Prodigy 20 points

According to your request, clearing the SOCHold99 flag can indeed increase the battery level to 100%, but the FC flag still cannot be set during charging. How can I solve this problem?

0 Anthony 7 months ago in reply to ? ??

TI__Mastermind 28470 points

Hello,

Can you please share a log file of the charge so we can look into why the FC flag is not being set?

Regards,

Anthony

0 ? ?? 7 months ago in reply to Anthony

Prodigy 20 points

Hello,Anthony

According to your request, I have exported the charging log, but the FC flag still cannot be set. Could you please take a look at where the problem lies? Thank you

3108.charge4.log

Regards,

+1 Anthony 7 months ago in reply to ? ??

TI__Mastermind 28470 points

Hello,

Since the FC Set% is -1, the gauge will use Primary Charge Termination to set FC, with the conditions seen below:

The Voltage is meeting the condition, however I see that there is a deadband of 5mA in the configuration. Is there a standby current that could be causing a change in capacity?

Regards,

Anthony

0 ? ?? 6 months ago in reply to Anthony

Prodigy 20 points

Hello,Anthony

The standby current is 20ua, and I think its impact on capacity can be ignored. I tried setting the FC Set% to 99 and observed that the FC bit was set. Although this is not the best setting for me, it is already usable.
Thank you very much for your answer!

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BQ27427: Why does the battery level stop at 99% during charging?