BQ27Z561-R2: Learning Cycle - Failure

Jainam Shah

Part Number: BQ27Z561-R2
Other Parts Discussed in Thread: BQ25306,

Hello,

I am using the 3.8V 385mAH battery with the Bq27z561-r2 module. I'm also using the Bq25306 module to charge the battery.

These are the parameters I have set as the learning cycle document and the battery datasheet.

Battery_parameters.xlsx

In this case, full charge is not occurring(FC bit not set). Charge term taper current, Quit current and Charge current threshold is set below 38mA. And the charging was stopped at the 60mA.

Is the charger IC(BQ25306) capable of providing 35mA(C/10) current?

I am sharing the log file of the learning cycle.

lc_logs_09_03.log

log_gg_09_03_2023.zip

Please let me know if any changes are require in parameter setting. Or do I need to change the charger module?

over 1 year ago

0 Jainam Shah over 1 year ago

Prodigy 50 points

Is there any update on this?

0 Ning T over 1 year ago in reply to Jainam Shah

TI__Mastermind 46611 points

Hi,

We are checking and will get back to you.

Thanks,

Ning.

0 Ning T over 1 year ago in reply to Ning T

TI__Mastermind 46611 points

Hi,

For the device, the termination current is clamped at 63mA if RICHG > RICHG_HIGH. Please refer to 9.3.2.3 Charging Termination for the details.

Thanks,

Ning.

0 Jainam Shah over 1 year ago in reply to Ning T

Prodigy 50 points

So, The charger module will not work with this battery.

Can you tell me how I can perform the learning cycle without charger IC?

And where I was stuck in the learning cycle of battery?

The learning cycle information is given above in this thread.

0 Wyatt Keller over 1 year ago in reply to Jainam Shah

TI__Guru** 102455 points

Hello Jainam,

Your learning cycle did not fail, you were able to update from 0x04 to 0x05 which means you got a Qmax update. Now you just need to perform relax-discharge at a rate around C/7 to update the resistance table.

Sincerely,

Wyatt Keller

0 Jainam Shah over 1 year ago in reply to Wyatt Keller

Prodigy 50 points

Hello Wyatt,

I have tried it but RDIS bit set at the discharge cycle, so Ra table is not updating.

If charging current is clamp at 63mA current which is >C/10 current of my battery. Is this causing the issue?

Can you tell me any other alternative way to charge the battery?

0 Wyatt Keller over 1 year ago in reply to Jainam Shah

TI__Guru** 102455 points

Hello Jainam,

Charging taper or charging current does not impact Ra table updates. It may affect Qmax updates but you have already successfully gotten Qmax updated.

Please share the new discharge log you completed. In the log you sent before it looks like Qmax didn't update until the discharge, which means you will need to do another discharge for Ra updates to be enabled, Qmax update is a pre-req for Ra table updates.

Sincerely,

Wyatt Keller

0 Jainam Shah over 1 year ago in reply to Wyatt Keller

Prodigy 50 points

Hello wyatt,

So, Is it okay to use the charging taper current and charging current threshold higher then c/10?

sharing the new log files,

1104.Log_LC_step1_discharge.log

5670.Log_LC_step3_charge.log

log_gg_13_03.zip

At the time of 2nd discharge RDIS bit was set. which stops the update of Ra table.

0 Wyatt Keller over 1 year ago in reply to Jainam Shah

TI__Guru** 102455 points

Hello Jainam,

Please share the most recent attempt for discharge testing, the logs you shared are the same as the previous, Qmax occurred on the charge and during the discharge Ra cannot update because Qmax had not updated yet.

The charge taper does not matter for Ra table updates.

Sincerely,

Wyatt Keller

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BQ27Z561-R2: Learning Cycle - Failure