BQ20Z655-R1: Soc changes at rest

Hi 

Can you verify that the soc reported by the gauge is incorrect, i.e the 10-20% being reported. The gauge in addition to the rest of your circuitry will continuously drain the battery, plus the battery self discharges as well.

Also, did you check to ensure you have IT enabled on your gauge? Was learning completed successfully?

thanks

Onyx

Hi,

Soc reported by the gauge is wrong. Cells are aproximately %50 but gauge calculates it %20. But it changes for all different batteries. Some of them shows less than %10, some of them shows %30, some of them shows %50. 

Cells self discharge and circuit consumption can not drain battery in 1 day. 

IT is enabled. Learning cycle is done. Update status is 0E.

But in my opinion, the problem is my production method. Because I cant find any clear information about how to program batteries on mass production.

TI explain well how to create a data, how to do learning cycle but there is no clear information about what I need to do after learning cycle!!!

I want to tell what I know about programming BQ20z655-R1 on mass production.

1. Edit data flash parameters.
2. Do calibration. 
3. IT enable by write 21 to manufacturer access.
4. Learning cycle untill uptdate status become 0E
5. Then export data flash parameters as an gg file
6. Upload default rom to that battery. 
7. Import that gg file which exported at step 5.
8. upload chem ıd
9. ?
10. ?
11. ?

I read some information about srec file. But how can I make a srec file from that learned battery? 

I want to produce batteries but there is no clear information in  here! Now, I upload that gg file to new batteries on mass production but I have a lot of gauge problems because of that. I want to learn correct way.

Could you help me about it ?

Hi,

I still have this issue. Batteries SOC changes at rest. Most of them shows incorrect SOC.

And also I couldnt correct way to program batteries on mass production? Is there anybody to help me about this?

TI explain well how to create a data, how to do learning cycle but there is no clear information about what I need to do after learning cycle!!!

I want to tell what I know about programming BQ20z655-R1 on mass production.

1. Edit data flash parameters.
2. Do calibration. 
3. IT enable by write 21 to manufacturer access.
4. Learning cycle untill uptdate status become 0E
5. Then export data flash parameters as an gg file
6. Upload default rom to that battery. 
7. Import that gg file which exported at step 5.
8. upload chem ıd
9. ?
10. ?
11. ?

I read some information about srec file. But how can I make a srec file from that learned battery? 

I want to produce batteries but there is no clear information in  here! Now, I upload that gg file to new batteries on mass production but I have a lot of gauge problems because of that. I want to learn correct way.

Could you help me about it ?

Hi

Like i mentioned in your other post, you can't program this device with an srec. It either has to be an senc, a .dfi or a .rom

the rom file which you extract from a unit that successfully completed learning already contains the chem id data. You do not need to program the chem id after you program this rom file. All you need do is program the rom file.

thanks

Onyx

Hi

1)I made a brand new pack and edited data flash values. Update status is 00 as default. Qmax values in Gas Gauging section are parallel cell count X cell capacity. 

2)Then I do all the steps in calibration section with writing 46x0006 to turn on mosfets on pro screen.

3)Then I write 21 in manufacturer access.

4)Then Fets are on.

5)Then I charged battery but it didnt terminate charging so I need to stoppped charging at cut off current of cells.

6)Then I wait 2hours and 15 mins. Update status became 05.

7)Then I am discharging battery now. I hope after 5 hour relax, update status will be 06.

8)If update status reach 06 after 5 hours relax, I will export datas and modified them. I will edit Update status 02 and cycle count 0.

9)Then I will write default senc file that I downlod from E2E forum. But I dont think it contains my chem data :) Is it right? Should I write default senc? When will I write my chem ID data? Do not I have to write chem Id data because I already run learning cycle ?

10)Then write modified gg file to board.

11)Then Read rom file on BqChem section. The rom file will be my production file.

12)I will write that rom file to new packs. Then Calibrate. Then send IT enable command with 21.

13) Then charge the batteries.

14)Then ship.

I am planning to do these steps. I hope my plan is right.

Please check my steps. If I wrong any of them, show me the way.

Fuel gauge is little bit challenge Onyx :)

Hello user,

I believe it is correct. It looks like you have gotten a correct Qmax update. I would recommend the next step is to make sure RUP_DIS bit is not set in the control register. It depends on if you have selected the right chemistry. However, your steps above look right to me. Make sure your discharge rate is above C/10 and below C/5 for best results.

The problem is still contiunes. 

Remaining capacity changes at rest even I wrote rom file with that steps.

Can somebody help me?

I cant produce new batteries with this TI BQ20z655-R1 chip so I cant sell batteries. And there isn't any support to fix problem. I already researched and found some documents and I did what I read. But still I am having an serious issue.

Hello user,

If temperature changes during the rest period, you will get RSOC jumps. Unfortunately for this device there is no method to prevent RSOC jumps in rest.

I would make sure your learning cycle/chemID is correct. Please attach a bqStudio or bqEVSW log to capture the jump and we can assist further.

Hi Kang,

I agree with you about temperature might be cause of RSOC jumps. But the room temperature is stable. I am aware that my programming procedure is not completely perfect.So I am trying to find best method. The last experiment, I programmed new batteries with rom file. Then I sent IT enable command. Then I discharged them all. Then I charged them. Then I discharged to %50 yesterday. Now its still %50 :) hopefully it will stay %50 after 3-4 days :) If it drops again, I will throw all batteries in the trash :)

I will let you know 3-4 days later :)

I have a question about chem Id. When I should upload chem ID data? Is learning cycle an alternative to chem ID data?

Hello User,

They are separate. Learning cycle is after you get the GPCCHEM report.

You upload the chemID data once you have a charge, relax 2 hour, discharge at C/10, relax 5 hour data log.

I have my .chem file. So when I need to upload it to battery? Before learning cycle? 

The ChemID needs to be updated first and then the learn cycle performed. Both of these are not optional and both are needed for a gauge to be accurate

Thanks,

Eric Vos

Hi Eric,

I have a battery pack that I uploaded chemId first then run learning cycle. Update status is 0E now. But the current goes between -3mA and 0mA. I think there was a problem on CC offset calibration before learning cycle. Unfortunately I can not trust that battery :) So I am thinking to run learning cycle again. 

But I want one thing from you that could you verify my programming procedure?

A) Creating a golden pack

1. Edit data flash parameters. (Update status is 00)
2. Upload Chem Id which downloaded from e2e.
3. Do calibration. 
4. Send IT Enable command
5. Run learning cycle untill update status become 0E
6. Then export data flash parameters as an gg file
7. Modify that gg file. (Update status 0E to 02, cycle count=>0, lifetime data to default)
8. Program that battery with default senc which downloaded from e2e to clear all datas. 
9. Import that modified gg file to battery.
10. Export rom file. This rom file will be my golden file.

B) Programming new batteries on mass production

1. Write golden rom file to new pack.
2. Calibration.
3. Send IT Enable command
4. Discharge completely.
5. Charge completely.
6. Ready to ship

This is my method that I am planning to test now. 

Can you check the steps ?

This looks to be a duplicate thread.

I asked similar questions because I couldt get answer on my older topic. You can attach or delete older topic. I will attach here my log files and gg files in here. But I need times (min 5 days) to happen that RSOC jump. Please do not lock this topic. 

user5503575,

Yes these steps look correct. Most do not do the charge/discharge in the mass production step, but it is better if there. I would add a 4b. rest step. 

I am running learning cycle now. I hope this time it will work.