BQ27426: Fuel gauge behavior during first battery charge

Yaron Apel

Part Number: BQ27426

Hi,

I have recorded the fuel gauge output values (state of charge, voltage, current...) during first battery charge after POR.

I have noticed that the state of charge and full capacity have a strange behavior when battery state of charge draws near 100%.

The state of charge if rising faster, while the full capacity has some kind of a 'knee':

Is this behavior expected?

Thanks,

Yaron

over 4 years ago

0 Yaron Apel over 4 years ago

Intellectual 290 points

0 Nick Brylski over 4 years ago in reply to Yaron Apel

TI__Mastermind 19195 points

Hi Yaron,

The device takes OCV measurement towards the end of charge which then updates the full charge capacity (fcc).

Best regards,

0 Yaron Apel over 4 years ago in reply to Nick Brylski

Intellectual 290 points

Hi Nick,

Thanks for your response.

In the Technical Reference I see OCV measurements are taken ater reset or in RELAXATION mode. Is there another document describing more
thoroughly the fuel gauge behavior?

If I track the fuel gauge flags, should I see any chage when this measurent is taken?

I see this phenomenon also when I use Qmax and RA table values taken from learning cycle. Should this have any affect on the fuel gauge behavior?

Thanks,

Yaron

Power management

Power management forum

BQ27426: Fuel gauge behavior during first battery charge