BQ25890: BQ25890 in Continuous Charging mode

Bhabu Bindu

Part Number: BQ25890

Hello Team,
We are working on a device that uses TI BQ25890 with LG INR 18650 Protected 3500mAh Single Cell Li-ion Rechargeable Battery (Specifications listed below),it is required that the device remains in continuous charging mode .

It has been observed that if the device is connected to continuous power supply even after being completely charged,device starts discharging after few hours.

And it has also been observed that while charging ,before getting completely charged the device at times goes to discharging mode, and if supply is reconnected after it has been in discharging mode for some time the device starts charging again.

Could you help us with the register configuration setting that could help us avoid this situation,and let the device be in continuous charging mode?

Best Regards,

Bhabu Bindu.

Battery Specification

Capacity (Ah): 3.4 Ah (3450mAh)

Energy (Wh): 12.6 Wh

Nominal Voltage (V): 3.6V - 3.7V

Charging Voltage (V): 4.2 V

Max. Discharge rate: 10A

Pulse current (5-6 sec.): 10A

Chemical Composition: Li-ion (Lithium-Ion) Hybrid

Cell model: LG INR18650 MJ1

External |welded PCB | Protection: Yes

Button Top: Yes

over 3 years ago

0 Ning T over 3 years ago

TI__Guru 57341 points

Hi,

Please check if the input source is over-loaded, either the current exceeds the input current limit or the VBUS pin voltage falls below the input voltage limit. When the input current limit or input voltage limit is reached, the device then reduces the charge current until the input current falls below the input current limit and the input voltage rises above the input voltage limit. Please refer to 9.2.6.3 Dynamic Power Management on the d/s and Extract maximum power from the supply when charging a battery (http://www.ti.com/lit/an/slyt569/slyt569.pdf) for the details.

This FAQ should also be helpful.

https://e2e.ti.com/support/power-management-group/power-management/f/power-management-forum/1025855/faq-bq25890-why-does-ichg-reduce-during-input-voltage-dpm-dynamic-power-management-or-the-input-current-dpm-for-the-chargers-bq25890-bq25890h-bq25892-bq25895-bq25895m-bq25896-bq25898-bq25898d-bq24190-bq24192-bq24195-bq24195l-

Thanks,

Ning.

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BQ25890: BQ25890 in Continuous Charging mode