BQ34Z651: Charging inhibited with no cause apparent

David Wright33

Part Number: BQ34Z651

Hi There,

I have a circumstance where charging is inhibited (as indicated by the XCHG flag in ChargingStatus [0x8000]). This is supported by the fact that current is dropping to 0 which indicates that both the CHG and ZVCHG FETs have been turned off.

However my SafetyStatus, PF and ChargingStatus registers are not showing any faults that would explain the XCHG state the pack is in and the pack temperature is comfortably sitting between JT1 and JT2 so temperature should not be forcing the pack into CHARGE-INHIBIT mode.

So I was wondering what else can cause the XCHG flag to get set. Because something is stopping the pack charging and I can't tell what.

Thanks,

David

over 6 years ago

0 Batt over 6 years ago

TI__Mastermind 42535 points

chg termination can cause chg current to drop to 0

0 David Wright33 over 6 years ago in reply to Batt

Intellectual 805 points

Hi there,

That was my first thought as well, but this is happening well outside the taper voltage range so a primary charge termination should be impossible. Also CHGFET is not set so a charge termination shouldn't turn off the FET.

Thanks,

David

0 Batt over 6 years ago in reply to David Wright33

TI__Mastermind 42535 points

Other than that if system present goes high, your chg can stop.

Power management

Power management forum

BQ34Z651: Charging inhibited with no cause apparent