BQ34Z100: Update Status not going to 05 and 06 even though DOD0 change is more than 90%

Hello,

Today's a national holiday. We will get back to you tomorrow.

Regards,

TI Apps Team

Hi Nick,

Thanks for letting us know.

Regards,

Srinath

Hello Srinath,

Looking back at the old thread. I want to apologize when you gathered the new ChemID 2153, there was a big issue that I overlooked when looking back at the data collected for the GPCCHEM tool.

For reference, this is the log file you shared with us.

2538.roomtemp_rel_dis_rel (1).csv

 The big issue I oversaw when looking at the data is after the discharge, during the relaxation state, the battery voltage is still decreasing which is indicating to me that there is still a discharge current being applied to the battery. We expect the opposite actually during the relaxation period. We expect the voltage to increase a little and then settle to a constant voltage. However, the voltage should not continue decreasing. It is very strange that the GPCCHEM tool reported back a ChemID however, this is still a mistake on my part for not catching that originally. 

You will need to redo the GPCCHEM process. This time, we need to verify that the voltage doesn't continue to decrease during the last relaxation part of the test.

Regards,

Nick Richards

Hi Nick,

We will proceed with redoing the ChemID process. This time I hope we can get this done, please do help us out.

Regards,

Srinath

And Nick,

I want to know how sure we can be this time that we get a proper chemID match? How sure that our pack undergoes a proper learning cycle? or should we look for any other gauge from other gauge family? Please help us out with what parameters we should change before the learning cycle in the data flash.

Regards,

Srinath

Hello Srinath,

If you can fix the issue with the voltage decreasing during the last relaxation then I am pretty confident that the GPCCHEM tool will report an accurate ChemID. Once you receive the new ChemID from the GPCCHEM tool, I will review all the settings before you start the learning cycle to verify everything. This gauge will be the best for the battery pack you are using.

Regards,

Nick Richards

Hi Nick,

Sounds good. Cycle is being done for GPCCHEM as we speak.

Regards,

Srinath

Hi Srinath,

Perfect, keep me updated.

Regards,

Nick Richards

Hi Nick,

Will keep you updated. We have some issues in our setup, might take a day or two to complete. Once done, will let you know.

Regards,

Srinath

And Nick,

One more thing, can we send our cell to TI to get characterized and get a chemID for our cell? What is the procedure for that? We will keep this cycle going on in one side and get our cell characterized simultaneously, either way its a win-win. Kindly let us know to proceed with it.

Regards,

Srinath

Hi Srinath,

Yes, you can send cells into TI to get your own ChemID for the battery you are using. If you get into contact with your local FAE, they will be able to assist you in starting this process. I will let you know that the process to get your battery characterized takes about a month to complete.

Regards,

Nick Richards

Hi Nick,

Will talk with my team regarding this and let you know whether we are sending cells for characterization or not. Other than that, our setup is now ready and we have started cycling for GPCCHEM tool. 

Regards,

Srinath

Hi Srinath,

Sounds good. Keep me updated on the results of the test.

Regards,

Nick Richards

Hi Nick,

We have got the report from the GPCCHEM tool. Attaching the report with the data from the cycle. We got a match for ChemID 7476 and 7671. Kindly check and let me know for whatever hiccups we had last time. I dont think we have any voltage drops during relaxation after discharge this time. Kindly let us know what parameters we need to change according to our pack. We have a 64 cell series pack. 24 Ah capacity.

Regards,

Srinath

8836.roomtemp_rel_dis_rel.csvchemID_cycle-report.zip

Hi Nick,

I need one more clarification. Would it be enough to just characterize a single cell or the whole pack? Kindly let us know what would give the best results.

Regards,

Srinath

Hey Srinath,

It will be enough to get just one cell characterized.

Regards,

Nick Richards

Hi Nick,

Did you check the GPCCHEM Report? Please do review our data for the discrepancies happened last time and also kindly confirm whether we can proceed with the chem ID 7476.

Regards,

Srinath 

Hey Srinath,

I just got a chance to look at the data and the only concern I have is that the battery did not go through a constant voltage charge after the constant current charge. As you can see the current just rapidly drops from 2018mA to 100mA. 

We expect the charging to look like this graph.

Where the current is slowly decreasing over time while holding the voltage constant at the the charging voltage for the battery, which I assume is 4.2 volts for your battery.

The rest after discharge looks good, so that issue was fixed. Now we need to fix the charging and the GPCCHEM tool should report back an accurate ChemID.

Regards,

Nick Richards

Hi Nick,

This is the supply issue I was mentioning. We will try to charge it fully again and hope the supply works properly on CC-CV mode. Will let you know the results. And we got in touch with the FAE team in India to send the cell for characterization. 

Regards,

Srinath

Hi Nick,

As you said, we re-did he charge and made sure to do CC-CV charge. Kindly check the data and the report and let us know whether the chemID is an accurate match or not. Hope there is no issues this time.

Regards,

Srinath

Chemistry ID selection tool, rev=2.54		
		
Configuration used in present fit:		
ProcessingType = 2		
NumCellSeries = 1		
ElapsedTimeColumn=0		
VoltageColumn = 1		
CurrentColumn = 2		
TemperatureColumn = 3		
		
Best chemical ID : 7671	Best chemical ID max. deviation, % : 2.27	
		
		
		
Summary of all IDs with max. DOD deviation below 3%		
		
Chem ID	max DOD error, %	Max R deviation, ratio
7671	2.27	0.89
7476	2.34	0.97
7583	2.95	0.74
		
Max. deviations for best ID is within recommended range. Chosen best chemical ID is suitable for programming the gauge.		
		
		
Selection of best generic ID for ROM based devices like bq274xx		
		
		
Device / Family #1		
Generic Chem ID	Device/ Voltage/ Chemistry	max DOD error, %
3142	bq27421-G1D: 4.4V LiCoO2	21.96
354	bq27411-G1C: 4.35V LiCoO2	23.96
128	bq27421-G1A: 4.2V LiCoO2	28.22
312	bq27421-G1B: 4.3V LiCoO2	34.29
Best generic ID 3142		
Warning: Generic ID Deviation is so high that it is most likely due to anomaly in the data. Please check that data files have recomended format, units and test schedule		
		
		
Device / Family #2		
Generic Chem ID	Device/ Voltage/ Chemistry	max DOD error, %
1202	bq27621: (default) 4.2V LiCoO2	23.57
1210	bq27621:  (ALT_CHEM1) 4.3V LiCoO2	23.92
354	bq27621:  (ALT_CHEM2) 4.35V LiCoO2	23.96
Best generic ID 1202		
Warning: Generic ID Deviation is so high that it is most likely due to anomaly in the data. Please check that data files have recomended format, units and test schedule		
		
		
Device / Family #3		
Generic Chem ID	Device/ Voltage/ Chemistry	max DOD error, %
3142	bq27426: (ALT-CHEM2) 4.4V LiCoO2	21.96
1202	bq27426: (ALT_CHEM1) 4.2V LiCoO2	23.57
3230	bq27426: (default) 4.35V LiCoO2	24.04
Best generic ID 3142		
Warning: Generic ID Deviation is so high that it is most likely due to anomaly in the data. Please check that data files have recomended format, units and test schedule		
		
		

0027.roomtemp_rel_dis_rel.csv

Hello Srinath,

Looks like the GPCCHEM tool has completed successfully and I would recommend using ChemID 7476. Program that ChemID and make any other changes that is needed in data memory. Once you finished all the configurations, send me the gg file as well as the data sheet for your battery and I will verify all the settings.

Regards,

Nick Richards

Hi Nick,

Thanks for confirming. I will attach the .gg file exported from EVM where I flashed the chemistry 7476. I will also attach the cell datasheet that we are using. Before that I have some questions:

1. ChemID 7671 had less error than 7476 why we need to go for 7476?

2. I think multiple data flashes have corrupted the data memory somehow because when I flashed the chemistry 7476 only Ra Tables changed and not the Q max Cell 0, so please check my .gg file. If its not proper can you send us the .gg file for us to import?

Pack details:

64S6P - 268.8 V peak. 24 Ah capacity. We want to taper at 265.6 V. Minimum Voltage for our application - 192 V (per cell 3V). Charge current 12 A (14 A Max.). Other than this do you need any other battery pack level information? Please do let me know.

Regards,

Srinath

TP-INR21700-40TG-Product-Datasheet-v1.4.1.pdf

flashedOnEVM_chem7476.gg.csv

Hello Srinath,

At the time of me writing that response ChemID 7671 was not available in the latest chemistry version. However, last night, Chemistry Version 1102 was made available publicly and this new version includes ChemID 7671. Therefore, it is perfectly fine to use ChemID 7671.

Since this is a matched ChemID from the GPCCHEM tool, we only care that the Ra table is updated properly. Qmax will be updated accordingly once the learning cycle is completed. 

I believe you need to change Design Voltage to 2700mV. I noticed that energy scale is 98. You will lose a lot of resolution with this parameter configured this way. However, we can revisit this parameter later. I believe once you make that one change, this should be ready to start the learning cycle.

Regards,

Nick Richards

Hi Nick, 

We will then update the chemistry and flash ID 7671 and make change to the design voltage as 2700 mV. Will attach the .gg file here after flashing. Please let me know if we should make any other change required to make it work for our battery pack specs. And please let me know till which voltage should I discharge the pack, at what rate and till what voltage should we charge it to. If you can get back to us today, we can start the cycle with everything in proper setting on Monday. About the energy scale, it was default value. Please let us know if we need to change it too.

Regards,

Srinath

Hi Nick,

As mentioned, we have flashed the chem ID 7671 on EVM and changed the design voltage to 2700 mV. I just want to know the reason behind 2700 mV? I'm attaching the .gg file here. Please go through it and let us know if we need to change anything else for a proper learning cycle. Also kindly let us know what should be my end voltages for discharge and charge and at what rates I need to do these.

Regards,

Srinath

flashedOnEVM_chem7671.gg.csv

Hello Srinath,

Yes, lets change energy scale to 10. Design Voltage needed to be set 2700mV because you are using a Volt Scale of 8. (3600 * 6 (number of cells in parallel))/ 8 (volt scale)

So you will need to charge up to 268.8 Volts, you can use a C/2 charging current (12 amps). Constant Voltage charge at 268.8 Volts until current reaches 800mA. Note, that in your current configuration, the gauge should be scaling down current by 10. So 12 amps real current should be reported as 1.2 amps by the gauge. If this is not the case, you will need to the correct current calibration. For discharge, I would discharge at 4 amps down to 160 volts.

Regards,

Nick Richards

Hi Nick,

Will change all these parameters in the data flash and start doing the cycle according to the end points you have mentioned. Will keep you updated with the changes.

Thanks,

Srinath

Hi Nick,

Design capacity should be 2400 mAh if I'm not wrong. Kindly confirm. And, we have a supply issue, we would be starting the cycle on wednesday at the earliest.

Thanks,

Srinath

Hello Srinath,

That is correct, design capacity should be 2400mAh.

Regards,

Nick Richards

Hi Nick,

Discharged the pack to 160V yesterday at 4A. Let it rest for more than 5 hrs. Now gave IT_Enable and RESET and started charging but VOK went high when RESET was given and the moment charging started VOK went low, is that concerning?

Regards,

Srinath

Hi Nick, 

Did everything according to the manual, still we have a unsuccessful learning cycle. Attaching all the logs. Kindly help us out here.

Regards,

Srinath

dsg_24-7.log

dsg_24-7_1.log

dsg_rel_24-7.log

chg_rel_25-7.log

chg_25-7_1.log

chg_25-7_2.log

chg_rel_25-7.log

after_chg_rel_25-7.gg.csv

Hello Srinath,

Thank you for sharing the files, please allow me some time to review them.

Regards,

Nick Richards

Hi Nick,

Take your time. Hoping for a solution.

Regards,

Srinath

Hello Srinath,

I am still looking into this. What puzzles me is that the FC bit gets set after full charge. This indicates that valid charge termination has been met. This is the sole requirement for LStatus to update to 0x05. I will need to discuss with the firmware team to see if there is any other requirements that need to be met for this.

Regards,

Nick

Hi Nick,

Thanks for the update, I hope you can help us with a workable solution.

Regards,

Srinath

Hello Srinath,

After talking with firmware team, we need to see if the Qmax value updates after charge. I will need you to run the test again, simply just the discharge, relax, charge, relax part of the test. But before the test, please save a gg file. And then save another gg file after the test. The Qmax value we need to see will be save in the gg file.

Regards,

Nick Richards

Hi Nick,

Will do the same and let you know. I think it will take us a few days to do the setup again. Give us some time. But the last time we did dsg_rel_chg_rel, I didn't notice any change in the Qmax Cell 0 in the data memory, it was the same as it was before.

Regards,

Srinath

Hi Nick,

What we think is somehow the data memory is corrupted, because how many ever times we flash the chemID 7671, we can only see the Ra tables changing, Qmax cell 0 is somehow 4000 and we dont know how. If it's possible, can you send us a fresh .gg file with the chemID 7671 flashed and parameters properly changed for our pack configuration so that we can import the same .gg file and run the cycle once again? 

Thanks,

Srinath

Hello Srinath,

Yes, I can work on getting you a fresh .gg file. I will need some time to get this for you.

Regards,

Nick Richards

Hi Nick,

Take your time. No issues.

Regards,

Srinath

Hi Nick,

Meanwhile I wanted to try something the past few days with the EVM and a single cell. Tried running a learning cycle for a single cell using the chemID 7671. The same happens with the single cell too. Checked Qmax Cell 0 before and after the cycle, I don't know why and how even after flashing the chemID 7671, the Qmax cell 0 is at 4000 mAh. Attaching the logs here.

Regards,

Srinath

dsg_31-7.log

dsg_rel_31-7.log

chg_1-8.log

chg_rel_1-8.log

afterchg_1cell.gg.csv

Hello Srinath,

Thank you for sharing this information. I am currently backlogged at work. I should get back to you next week.

Regards,

Nick Richards

Hi Nick,

Hoping to get a solution probably in the next week beginning.

Regards,

Srinath

Hello Srinath,

We are looking into this and will get back to you on Monday.

Regards,

Siddharth

Hi Siddharth,

Thank you for letting us know. Hope we can get a solution today.

Regards,

Srinath

Hello Srinath,

There is a shortage of BQ34z100EVM for our team. I am still trying to find one to use so I can send you an updated gg file.

Regards,

Nick

Hi Nick,

I can understand. Kindly get back to us as soon as possible.

Regards,

Srinath

Hello Siddharth,

I'm not sure how the srec file will help us, can you brief me through? I thought you would send us a .gg file which we could import into our gauge.

Regards,

Srinath

Hello Siddharth,

Okay is this the golden image that I just need to program into our gauge?

Regards,

Srinath