BQ2980: WHen Charger is connected Charging is not done

Virendra Shah

Part Number: BQ2980
Other Parts Discussed in Thread: BQ24600

I have designed Li-ion battery Protection using BQ2980. I have used reference schematic of BQ2980.

During Normal DSG FET and CHG FET both are ON but when I connect Charger, charging is n't started. I am using 3A charger built using Bq24600 for 1S6P Li-ion Cell.

What will be the possible cause for this? What is voltage difference is required between Battery Voltage and Charger voltage so that Charging is started?

Is there any limitation of charging Current?

When I bypass Protection circuit charge circuit works perfectly.

Regards,

Virendra

over 5 years ago

0 Shawn Hinkle over 5 years ago

TI__Expert 7465 points

Hi Virendra,

When your charger is connected, do both of the FETs remain on? If not, it is possible there is some sort of fault occuring.

For the charger to be detected, the charger voltage (VPACK) must be 700mV greater than the battery voltage (VBAT).

0 Virendra Shah over 5 years ago in reply to Shawn Hinkle

Prodigy 190 points

Hi When Charger is not connected and Load is connected at that time both FET's are On, is it OK?

But When Charger is Connected at that time DSG FET is Off, only CHG FET is ON, is it right status of the FETs?

FYI: In my case Difference between charger and Battery pack is < 0.7V , in that case CHG pin toggles.

0 Shawn Hinkle over 5 years ago in reply to Virendra Shah

TI__Expert 7465 points

Hi Virendra,

The state of the FETs depends on the cell voltages, but the scenarios you have described sound generally correct.

Power management

Power management forum

BQ2980: WHen Charger is connected Charging is not done