BQ25302: BQ25302RTER Battery Charging Issue when Battery Volt <2.55V

Eugene Ong

Prodigy 80 points

Part Number: BQ25302

Tool/software:

Customer is using BQ25302RTER charger IC in their project.

When the battery cell <2.5xV, the VSUB charger can’t charge the battery cell, the indictor LED always blinking.

If the voltage above 2.8V ~ 3V,the battery charger IC can charge.

6 months ago

0 Ning T 6 months ago

TI__Guru 56341 points

Hi,

Is there any battery protection circuitry in between BAT pin and the battery pack or does the battery have built-in battery protection?

Thanks,

Ning.

0 Eugene Ong 6 months ago in reply to Ning T

Prodigy 80 points

HI Ning,

Yes, the battery pack with built-in battery protection circuit.

The cut over discharged too lower.

The reading of the VBAT just 2.07V and no see any current follow charge the battery cell. (after inserted USB plug 5V (VSUB))

Is that if the battery voltage <2.5V and IC chargers can’t charges or ?

0 Ning T 6 months ago in reply to Eugene Ong

TI__Guru 56341 points

Hi,

When the battery pack voltage is too low, the battery protection may disconnect the battery pack from the BAT pin of BQ25302 (i.e. the BAT is open), so the charger is unable to charge the battery. Please check the battery protection specs for how to re-connect the battery to the charger. The e2e thread below should give you some idea.

https://e2e.ti.com/support/power-management-group/power-management/f/power-management-forum/918969/bq25895-strange-behaviour-of-bq25895-s-vbat-output

Thanks,

Ning.

Power management

Power management forum

BQ25302: BQ25302RTER Battery Charging Issue when Battery Volt <2.55V