BQ27425-G2A: About battery level detection after system reset or battery change

Y.Ottey

Other Parts Discussed in Thread: BQ27425-G2A

Dear TI Team

I would like to ask about operation of BQ27425-G2A.

We have confirmed in the data sheet that the battery level is predicted by the following method.

"The bq27425 device measures charging and discharging of the battery by monitoring the voltage across a small value integrated sense resistor (10 m Ω, typical) located between the system VSS and the battery’s PACK– terminal."

For the remaining charge after battery replacement or system reset, is the voltage measured in the same way as above to predict the remaining battery charge?

Best Regards,

Y.Ottey

over 5 years ago

0 Andy Liu (BMS) over 5 years ago

TI__Guru 52115 points

Actually, that sentence describes how the gauge measures the discharge or charge current.

The Impedance Track algorithm applies QMax, impedance, temperature, voltage, and current data to calculate the remaining capacity.

Andy

0 Y.Ottey over 5 years ago in reply to Andy Liu (BMS)

Mastermind 6145 points

Dear Andy

Thank you for your reply.

I understand that I apply QMax, impedance, temperature, voltage, and current data to calculate the remaining capacitance.

For example, when calculating the remaining capacity after changing the battery or after resetting the system, may there be a difference from the original remaining capacity of the battery?
(Affected by the battery before change and the state before reset)

Regards,

Y.Ottey

0 Andy Liu (BMS) over 5 years ago in reply to Y.Ottey

TI__Guru 52115 points

I would suggest you read the following app note, which explains quite a lot of details of Impedance Track algorithms.

https://www.ti.com/lit/an/slua364b/slua364b.pdf

Andy

Power management

Power management forum

BQ27425-G2A: About battery level detection after system reset or battery change