BQ20Z70-V160: BQ20Z75: PACK CHG & DSG disable

Steel Fang

Intellectual 300 points

Part Number: BQ20Z70-V160

Dear TI expert,

we received several bad packs from customer, accroding to customer,the pack can't charge.

we checked that the CHG & DSG are disabled, see blelow picture.

can you help to analyze the possible causes?

CHG & DSG are enabled before shipment.

thanks.

over 1 year ago

0 Wyatt Keller over 1 year ago

TI__Guru** 105760 points

Hello Steel,

From the screenshot it looks like both FETs should be enabled, there are no protections tripped and XCHG and XDSG are 0, which means the firmware wants the FETs turned on. Please make sure the manual toggle of the FETs is not used.

Sincerely,

Wyatt Keller

0 Steel Fang over 1 year ago in reply to Wyatt Keller

Intellectual 300 points

Hi Wyatt,

No manual toggle of the FETs is used, we just found it could not charge and no OCV.

0 Wyatt Keller over 1 year ago in reply to Steel Fang

TI__Guru** 105760 points

Hello Steel,

That is the only possibility I see for this type of issue. Or the gauge was power cycled or damaged in some way.

Sincerely,

Wyatt Keller

0 Steel Fang over 1 year ago in reply to Wyatt Keller

Intellectual 300 points

Hello Wyatt,

What does power cycled mean? the gauge is not damaged, we can manual enable it and it works well.

will the transporation can occur such issue?

0 Wyatt Keller over 1 year ago in reply to Steel Fang

TI__Guru** 105760 points

Hello Steel,

Power cycle means the gauge lost power and then regain power. So if you manually enable the FETs and then a safety event occurs does it toggle the FETs correctly? It seems they may have been manually toggled by accident.

Sincerely,

Wyatt Keller

0 Steel Fang over 1 year ago in reply to Wyatt Keller

Intellectual 300 points

Hi Wyatt,

yes, once manual enable the FETs, they will work correctly with full charge/full discharge.

except the SMBUS command to enable the FETs, any other way to enable them?

0 Wyatt Keller over 1 year ago in reply to Steel Fang

TI__Guru** 105760 points

Hello Steel,

It seems the commands to enable the FETs may not have been sent if they are working normally when manually toggling them.

Sincerely,

Wyatt Keller

Power management

Power management forum

BQ20Z70-V160: BQ20Z75: PACK CHG & DSG disable