BQ24074: Pin of TMR

Denny Huang

Part Number: BQ24074
Other Parts Discussed in Thread: BQ27Z561-R2, , BQ28Z610

Dear Team

The customer accord the battery spec and design the charge current, then they may expect the time of battery full charge.

And they use Pin 14 (TMR) to set an timer, If battery is not full charge at expect the time and the ic will indicates a fault condition.

1. The fault condition can be a foundation to inference the damage from battery cell?

2. If TI have other charge solution which have function could detect the damage of battery directly?

Many thanks

Denny

over 4 years ago

0 Garrett Kreger over 4 years ago

TI__Mastermind 31050 points

Hi Denny,

The safety timer expiration faults main purpose is to prevent the battery from charging indefinitely. While the timer fault could indicate damage to the battery a safety timer expiration could also be due a high system load preventing completion of the charge cycle.

TI do have battery fuel gauge products with battery state of health (SOH) monitoring. The BQ27Z561-R2 is a potential solution which can directly detect battery damage.

Regards,

Garrett

0 Denny Huang over 4 years ago in reply to Garrett Kreger

TI__Expert 7170 points

Hi Garrett

Thanks your recommend.

The customer use BQ24074 and BQ28Z610.

Is BQ28Z610 have function of state of health (SOH) monitoring?

Many thanks

Denny

0 Garrett Kreger over 4 years ago in reply to Denny Huang

TI__Mastermind 31050 points

Hi Denny,

Yes the BQ28Z610 has state of health monitoring. The battery (SOH) is reported by the StateofHealth() command.

Regards,
Garrett

0 Denny Huang over 4 years ago in reply to Garrett Kreger

TI__Expert 7170 points

Hi Garrett

Thanks your recommend.

The customer use BQ24074 and BQ28Z610.

Could you help to recommend the questions?

1. What is the proper way to handle a charge timeout given that we have both a gas gauge and charge IC?
2. Would you recommend using the SOH value to determine the health of the batteries?

Many thanks

Denny

0 Nick Brylski over 4 years ago in reply to Denny Huang

TI__Mastermind 19195 points

Hello Denny,

The charge timeout is documented in the bq28z610 TRM sections 2.12 / 2.13: https://www.ti.com/lit/ug/sluua65d/sluua65d.pdf . for more detailed questions on this topic you will need to make a separate post
Yes, the SOH metric can indicate battery health. State of Health is calculated using the ratio of Full Charge Capacity and Design Capacity. Older batteries with lower FCC than what they were originally rated for have lower state of health.

Best regards,

Nick

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BQ24074: Pin of TMR