BQ20Z95 question

Mike_chute

My battery pack is starting to see a few DFF set. I have set an senc file to TI to verify the file was not corrupted. It was not. I can clear the DFF flag with a reset permanent failure command. Would I be compromising the pack safety by doing that?

mike

over 12 years ago

0 ThomasCosby over 12 years ago

TI__Guru 73830 points

Mike

Does the DFF fault keep getting set on the same device? If so, it may be defective. It can be caused by a checksum verification problem or failure to communicate with the flash memory.

Tom

0 Mike_chute over 12 years ago in reply to ThomasCosby

Intellectual 825 points

Tom

We are seeing the DFF flag set when the cycle counter increments. Is that possible? I thought the cycle counter increments during the rest time when no current is drawn from the battery.

Mike

0 ThomasCosby over 12 years ago in reply to Mike_chute

TI__Guru 73830 points

Mike,

The Cycle Count will update after the passed charge meets the accumulated discharge criteria. It will update during discharge.There should not be a connection between Cycle Count and a DFF fault. The DFF flag will get set when there is a DFF contents or access problem.

Tom

0 Mike_chute over 12 years ago in reply to ThomasCosby

Intellectual 825 points

In the Z95 application guide Figure 2-6. 2nd Level Protection it shows "PFClear to ManufacturerAccess" We are seeing the cycle count bump, the DFF flag set and the cell revision register changed from 5000 to 0. Why would the z95 clear our cell revision register?

Mike

0 ThomasCosby over 12 years ago in reply to Mike_chute

TI__Guru 73830 points

Mike

The firmware will not change data in the Cell Revision register to 0. This must be an artifact of whatever is causing the DFF fault.The "PF Clear to MAnufacturerAccess" that you mentioned is a code that can be used to clear the PF fault flags.

Regards

Tom

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BQ20Z95 question