BQ34Z100 Learning cycle

Jake,

I reviewed your log data and setup file. Your procedure looks okay, but I see a few things that could affect the results.

1. You have a 2-cell configuration and the Number of Series Cell parameter is set to 2, but the VOLTSEL bit is not set in the Pack Cfg A register. It should be set when the stack voltage is greater than 5V. You will need to set the bit and calibrate the pack.
2. The Cell Term Voltage is set to 3000mV, but you are discharging to 2729mV. Do you want SOC to reach 0% at a 6000mV pack voltage? You can discharge lower than the 300mV below the Cell Term V, but this can lead to Passed Charge issues during ormal operation, if you do not always have a rest period.
3. The Taper Current is set to 100mA, but the Current does not drop below this threshold while charging. You should probably let the charge continue until the Current reaches about 50mA.

Tom

Hi Tom.

First of all thank you for your prompt answer.

I've updated board setting by your recommendation and tested it again.

But, Still I can't see update status is changed to 0x05.

Can you check the log file and gg file again to check what I need to do for right 4300.20140709.ziplearning cycle?

Any comment for my case?

I checked the discharge data with my Mathcad program and it does not show ChemID 107 to be a good match. Did you select this ChemID, because it is the default ChemID loaded in the device? The rest times are not long enough to make a good judgment, but the program shows ChemID 2018 to be a better match. I would try this one.

You are also using a very high charge and discharge rate for an optimization cycle.

Change the FC Set % parameter setting to -1 to set the FC flag after the Taper Current has been met.

Use this modified sequence this time to allow more rest time.

1. Discharge to empty

2. Wait until the OCVTAKEN flag turns red. Let is rest for at least 1 hour.

3. Send IT Enable command to set a DOD0 reference point.

4. Charge to full at a C/5 rate. (FC bit set.)

5. Wait until the OCVTAKEN flag turns red. You should see VOK turn green after Qmax has learned. You should see Update Status change to a 05. Let is rest for at least 2 hours.

6. Discharge at a C/8 rate down to Term Voltage.

7. Wait until the OCVTAKEN flag turns red. You should see Update Status change to a 06 during the rest period. Let it rest for at least 2 hours.

I can provide a better ChemID check with the longer rest times, but hopefully the gauge will update this time.

Regards

Tom

First of all, Thank you. Tom.

I've done learning cycle with doing below changing list.

Would you let me know what is effective behavior for making learning cycle done among below changing list what I've done

And let me have right chem ID. You can refer to the attachment that has been done with your recommendation.

1. Voltage divider : I used EVM with 16V setting. So, I've changed to 8.4V

2. Qmax Cell was changed to 2000mAh manually.

3. All calibration has been done. In previous test, I've just performed a few part of calibration

4. Changed chem ID from default to 0218

5. didn't send 0x21 and 0x41 before having discharging for the first time.

Thank you very much.

6012.bq34z100_learning_done_20140716.zip

any response?

Please update for my case.

Jake,

I checked the log data and it is much better to run a ChemID analysis. Mathcad shows ChemID 285 to be a good match for the log data and ChemID 2018 could have a potential negative resistance issue. Your optimization cycle ran, but you could have problems in the future. I updated the attached gg file with the Ra table and Qmax that you would see, if you were to run a new optimization cycle. You can reload the default bq34z100 senc file, load ChemID 285 and load the attached gg file. Then, issue a reset (41) command, recalibrate and send an IT Enable (21) command. You can then charge and discharge and check the gauging accuracy.

Tom

Hello Mr Cosby,

I would like to know if TI has created an official document to a process for the learning cycle? 

Thanks,

Julien

Ok Thank you TOM

Hi Thomas,

Were you able to prepare the document? (about learning cycle)

You say that it is normal to see VOK in green after the learning cycle. But is it normal that stays green all the time?

On three batteries, after the learning cycle, the maxerror is equal to 3% (so, Ra_Table is not updated). However Update Status = 06. Do you have an explanation?

Something else. We wish to have Learned Status = 06. But in paragraph 7.3.2.23 of the datasheet: IT is enable and CF1, CF0 = 1, 0. (Case not taken into account).

After a learning cycle, Learned Status should be equal to 0C or 0D, no ? Qmax updated + IT enable.

Batt 1

Batt2

Batt3

BR.

Thomas, 

Unfortunately the recordings did not work. BQstudio initiated the registration without creating the file.

But I also come back to chemistry. Can you tell me the differences between the chemistries ID1323 / ID 2102 and ID2131 ?

Why 3 chemistries for the same cell?

Best Regards