Wakeup Dead batteries via DA14681

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mahmed106
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Wakeup Dead batteries via DA14681

HI dialog

We are working on two custom boards based on DA14681. One has external charging ic "MP26029" and other is using DA14681's internal charging setup.

The problem which we are facing is that when customer dont use the device for a long time, battery's voltage drop too much. sometime it goes to 0.8V or 0.6V.

Then when we plug in the charger, DA14681's charger is not able to charge the battery, even after 24 hours of plug in the charger, but other board that has external charging IC, that charges the battery within 4 5 hours.

Please find the attached pdf of the charging settings.

 

Device: 
PM_Dialog
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Hi mahmed106,

Hi mahmed106,

Thanks for your question. Let me check it and I’ll get back to you.

Thanks, PM_Dialog

PM_Dialog
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Hi mahmed106,

Hi mahmed106,

Could you please indicate the battery part number that is used in your design? Additionally, would it be possible to share a screenshot with the battery voltage when the battery changing is enabled and the battery is at 0.6V-0.8V?

>>>The problem which we are facing is that when customer dont use the device for a long time

In that period the system is in sleep mode?

Thanks, PM_Dialog

mahmed106
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System goes  to sleep mode

System goes  to sleep mode when battery drops below 3V.

Please find the attached battery document.

Attachment: 
PM_Dialog
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Hi mahmed106,

Hi mahmed106,

Thanks for the update. I'll escallate the question internally to Team.

One more question : what is the SDK version? Is it SDK1.0.14 ?

Thanks, PM_Dialog

mahmed106
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yes 1.0.14

yes 1.0.14

PM_Dialog
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Hi mahmed106,

Hi mahmed106,

The used battery is having a PCM (protection circuit module), so how is possible to have 0.6V-0.8V on VBAT?

The problem is the over-discharging of the battery. If the VBAT drops below the minimum voltage but exists some voltage (like the 0.6V mentioned here) the 68x when there will be any trigger to wake will fail to start the RC32K LP clock and will never exit the reset phase. In this case, the chip can recover operation only if VBAT and VBUS are totally removed and the decoupling caps on VBAT are discharged.

A quick could be done is the following:

- de-solder the battery carefully.

- what is the battery terminal voltage after the de-soldering?

Two cases:

1) if still ~0.6 V: then apply a voltage of 3V to 4V to the battery terminals for a short time (~1sec) for trying to un-lock the battery.

    - Has the battery voltage restored now? If true, the battery has been un-locked. What is the battery voltage?

          => the PCM might have some leakage causing a residual voltage at Vbat.

    - When the battery voltage did not change, and still reads 0.6V, the battery voltage really is 0.6 V I think.  

          => as such the PCM might not have triggered. PCM is not functioning as expected.

 2) In case the battery voltage has increased after the de-soldering (>> 0.6 V), the battery has been un-locked.

     -  What is the battery voltage? => the PCM might have some leakage causing a residual voltage at Vbat.

Thanks, PM_Dialog