BQ20Z655-R1: Charging and discharging issue

hello I think It is because I do not have correct chem. i have to do chemical selection again, before, can you tell me if the data. csv file, I should register information from the BQ and the battery directly or should I create this file from external measure ?

regards

The log data for chemical ID matching can be collected using bqStudio or other equipment. The data will be the same.

Hello Shirish, few questions :

During the Chem selection, I do a charge discharge as specified in the slva725a. Can you confirm that is the first step to do before selecting good parameters in the data flash ?

As specified in the slua903, after choosing chem by GPCCHEM, I will do a learning cycle by writting the correct data ( taper current, current threshold, quit current, term voltage ...)?

hello Shirish,

we have the BQ20z655 R1, with the software texas instrument bq gas gauge evaluation software v0.03, do you think it is possible to have a latest software version which will be working with our BQ ?

Do you know cells from samsung 35E ? is it possible to directly get the chem id ?

Do you think it is possible to have a newest list of chem than the one in our software ? it is only very old cells.

regards

Hello Gus,

The latest version of evaluation software is at https://www.ti.com/product/BQ20Z655-R1

You can update the chemistry list for evaluation software by installing the update from https://www.ti.com/tool/GASGAUGECHEM-SW#downloads

hello Shirish,

now I well have the chem version 960.

I install the update of the chemistry,

when I click on : OK update fuel gauge data flash

I have the default message : error at match template : Cannot find the device encr file.

Hello Gus,

Can you try uninstalling bqEVSW and deleting the install folder?

Then install bqEVSW and the chemistry updater.

Hello Shirish,

I do all the chem selection, it works very well,

I do the learning cycle until update status is 0E,

Qmax cells is very good value but full charge capacity does not update.

Hello Gus,

Take a golden image at this point and then run cycles to verify accuracy. Normally Full charge capacity should have updated. It is  dependent on Qmax. Check it during cycling for accuracy.

should I do next run cycles with some manufacturer access code ? like 21 ? because my Qmax are all right I have 10188mAhbut in Full charge capacity I have 7793mAh :

Hello Gus,

No need to send any commands. Just full charge and discharge cycles in your application (or similar to learning).

Hello Gus,

Full charge capacity(FCC) has changed  from previous value. You can see this by comparing the 2 screenshots that you posted. So the gauge is calculating and updating it.

The system parameter settings in data flash determine how much capacity of the battery is usable. The calculated usable capacity is returned in FCC. A higher termination voltage will reduce FCC.

Yes but it so far from the 10500 mAh therical and 10200 mAh calulated That I want to reach. Which parameter should I modified to set the right FCC ?

Hello Gus,

It comes down to matching the battery to the application. The capacity in the battery datasheet is under a specified load. If the application has a different load, then the capacity of the battery for that use can be different.

But I do not understand why I have measured a discharge capacity at 10200mAh, A charge capacity at 10350mAh but I Always have only approximately 7829mAh. roomtemp_rel_dis_rel.xlsx

Hello Gus,

Thanks for attaching the log. I will take a look at it today.

Hello Gus,

I took a quick look. At this load, the battery has more capacity than the reported FCC. Is this the application load?

Send me your GG file for analysis if this is how the application load looks like.

Yes exactly, here is mu .gg file :

https://we.tl/t-i9YeTGEhwk

I do not succed to add the .gg file to the forum, so I make a wetransfer link, i hope it will be ok for you.

Hello Gus,

I am blocked from accessing the link. Please see this post for uploading files to the forum

https://e2e.ti.com/support/site-support-group/site-support/f/site-support-forum/761619/faq-how-do-i-attach-a-file-or-link-to-my-post

apprentissage 170522.zip

Hello Gus,

Thanks. The GG file shows lifetime data values that are not normal for a learning cycle. It looks like FCC may have been set when there was an incorrect cycle.  In such cases, it will take many cycles for FCC to reach the correct value. Try sending command Reset (0x0041) TRM section A.1.2.11 and let me know if that makes any difference. Otherwise you may need to redo the learning by using a fresh bq20z655-R1.

Hello Shirish,

We send 0041 to manufacture access, the FCC grows to 8.1Ah but still far from our 10.3Ah.

Hello Gus,

It is best to redo the learning cycle by setting update status to 0 and reprogramming all data.

Hello shirish I have many questions :

With a fresh bq20z655-R1, I conect it to my battery, then I connect it to the evaluation software, I send the chem that I found on last time. I check parameters : design capacity, design voltage, charge term taper current, dsg current threshold, chg current threshold, quit current and term voltage.

I write all the data.

therefore it is impossible to charge or discharge the battery.

I then try to do 0021 et 0041 manufacture access to get gauge_en and reset.

I do not know how to read bit gauge_en ?

I have then this screen, I'm well in update status 04. How can we update the update status to 00 ?

I have this OTA set 1 which is strange because my temperature is between Jt2 et Jt2a ?

Know I am blocked because I cannot still charge or discharge when I connect my battery to charger.

Hello Gus,

Charging is blocked because of OTA flag. That will need to be resolved. Check the OT thresholds in data flash.

Did you mean IT_enable instead of Gauge_en? IT_Enable is QEN bit of Operation status.

Did you get update status 04 without doing any learning? If yes, then that is strange. You can write it to 0 from data flash screen.

For my OTA flag, I have good OT thresholds, I just do a calibration and the flag disappear.

Yes i have the status 04 after learning chemistry by BQ chem and when i try to update it at 00 it make " run time error : 13; type mismatch"

Hello Shirish,

now I am at update status 05,

I finish the charging at C/2, after two hours rest, VOK goes to 0 and Qmax for cells updated,

Now I try to launch the discharge but it seems battery is blocked, discharge is not beginning, VOK stay at 0; should I do something more to launch the discharge ?

regards

Hello Gus,

Safety Status has SCD flag set. Looks like there may be a short circuit condition that you will need to resolve. TRM reference section 2.2.3 Short-Circuit Protection

How to change update status ? When I try to write in data flash it appears run time error'13': type mismatch

Hello Gus, I am not sure why you see that error. You can try uninstall + reinstalling bqEVSW

I did it but me and my collegue on different computer had the same issue, Do you have idea about a state of the battery that can arrive ?

And can you explain me what are the solution to erease the OTA and TDA flag that appear in all my new BQ with enough high value in Over temperature to do not disturb it and having done a calibration to register the right temperature value ?

regards

Hello Gus,

Are you using the TI EVM for this?

I m using TI EV2400 HPA 500 MSP 430 controlled

With a bq20z655EVM?

Sorry to ask again - need to know where the bq20z655-R1 is physically installed. If you purchased a TI EVM with the bq20z655-R1, then that is a good reference as we know all the details. If it is mounted on your own board, then there can be other variables.

Yes it is mounted on my own board.

Do you think we can have a web meeting ?

regards

Yes, I sent you a friend request. Will send the meeting link via DM

Yes I accept it.