BQ20Z655-R1: No capacity after creating golden unit. Weird charging

JDrulia

Part Number: BQ20Z655-R1

I created a golden unit following SLUA379E. I then discharged the unit down to cutoff.

During the next charge cycle, I noticed it was charging intermittently. I've included the log file showing the weirdness.

I decided to reprogram the pack with a fresh .senc and upload my .gg. I sent a reset (0x0041) but now I show no capacity.Golden_Data_Charge_Capacity Issue.zip

What is going on? Other possible pertinent info - right now I am using the default chemistry because I cannot get the Mathcad file to work...

over 8 years ago

0 ThomasCosby over 8 years ago

TI__Guru 73830 points

The log file shows that the COV fault is getting triggered due to the charging voltage being set too high. The cells have been charged to too high of a voltage and may have been damaged.

0 JDrulia over 8 years ago in reply to ThomasCosby

Intellectual 385 points

I saw that. I measured the cells at the same time the COV fault is happening and the cells are measuring almost a full volt lower (~3.6V). Would a default ChemID cause these issue?

0 ThomasCosby over 8 years ago in reply to JDrulia

TI__Guru 73830 points

The ChemID does not affect the Voltage readings. That would be a voltage calibration problem. You can try calibrating the voltages.

0 JDrulia over 8 years ago in reply to ThomasCosby

Intellectual 385 points

Calibrating did fix the COV faults. But after another discharge cycle from full, I am now charging the unit and RSOC is not updating.

0 ThomasCosby over 8 years ago in reply to JDrulia

TI__Guru 73830 points

The RemCap should increment based on coulomb counting. It can bet set to 0 at that voltage due to the ChemID as well. Whcih ChemID do you have loaded and have you verified that it is a good match to your cells? Also, you mentioned that you have prepared the golden pack. The gg file indicates the Qmax and the Ra tables have not been updated, so the data flash is not ready to create the goldne pack yet. How did Update Status get set to 06?

0 JDrulia over 8 years ago in reply to ThomasCosby

Intellectual 385 points

I am having an issue with the MathCAD, so I am just using the default ChemID. Can I send you cells to characterize and tell me which is the best ID? How do Qmax and Ra get updated? Why is there no bqEasy for the BQ20Z655-R1?

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BQ20Z655-R1: No capacity after creating golden unit. Weird charging