BQ40Z80: Learning cycle procedure values confirmation

Hello Wyatt ,

thanks for your reply.

I just started the learning cycle , discharging is completed REST bit is set so i just put the charging after charging FC bit and VCT bit also set , then i put relax mode for the day.

i here by attach my log , for your refernce , could you please verify whether up to the level my process is success or not. ? waited up to 2 hours REST bit is not set after 2 hours , hope it will set whether any mistake i did in the steps , please verify my logs and let me know.

64157.log.zipBqlog.log

Hello Wyatt ,

Friday i put the board for Relax mode after discharging while i came back on monday (Today ) mng  REST bit is set . but L status is not changed to 05, still it is in 04 (The battery dropped its charge to 11.5 V from 12.5). Eventhough i just started the battery put discharging (C/5 rate ) . After the discharging RELAX bit is set but L status not changed . Friday leaving time i took the PC so i cant log  the balance log . Today i just started from the dischagring state.

I am sharing the logs with you . Could you please check and help me why the L status is not changing eventhough REST bit is set ??

Could you please help me find out  what mistake i did in procedure ?

Let me know is there any issue in my configured parameters.?   (now i completed discahrge - relax-charge-relax- doscharge- relax) procedure.

Log.rar

Charge term taper current : 140 MA

Dicharge current Threshold : This is the current threshold above which the gauge detects that it is in discharge mode :  30MA

Chg Current Threshold : This is the current above which the gauge detects that it is in charge mode  :         40 MA

Quit Current : This is the threshold that determines that the gauge enters relax mode : 15MA

Term voltage : 3x3v = 9v

Design Voltage : 3 * 3.6 v = 10.8 V

Design capacity : 2600 MAh  (serially connected 3 Cells)

Let me know why my Ra_Table is not updated properly.??  This is my BMS circuit diagram please identify the issue ,our project is in last phase

Hello Mohan,

Update status from 0x04 to 0x05 indicates a Qmax update, not an Ra table update. For Qmax update you must have 90% change in DOD between the two relaxation periods when the gauge takes the OCV and updates DOD0. 

The log is not a full log, I cannot determine any issues from it since it is only showing about 1.5 hours after discharging stopped.

Sincerely,

Wyatt Keller

Hello Wyatt ,

why my Ra table is not updated . Can you check my attached log , this is my 2 nd stage discharge cycle log. Could you please check and let me know why the Ra table is not updated in the charging cycle.

8407.Log.rar

Hello Mohan,

You must get a Qmax update before the Ra table will update, make sure to follow the learning cycle guide that is linked on the other threads. You are not following the correct procedure outlined in SLUA848.

Sincerely,

Wyatt Keller

Hello Wyatt ,

Please confirm the procedure . This is the procedure i am following if any correction is required let me know ?

In first discharging when i am sending the RESET command VOK bit will clear automatically is that one will be any problem ?

1. Flashed the ChemID
2. Configure the parameters required for our learning cycle.

3. Started with Discharging procedure.  
4. Send CHG_FET_TOGGLE and DSCHG_FET_TOGGLE Command until CHG and DCHG bit are red.
5. Then send GAUGE_EN bit  IT status changed to 04
6. Send RESET command  that time VOK bit is cleared and RDIS flag is set
7. Connect the setup to load setup ( C/5 ration is taken as discharging Rate  2600Mah/5 = 0.520 Ma)
8. Enable the DCHG_FET through the DCHG_FET_TOGGLE Command
9. Discharge the battery until until the voltage at the top of stack reaches the Term Voltage and gauge report 0 %.
10. FD bit is set when fully dichagred
11. Turn off the DCHG_FET
12. Relax mode (5 hours recommended)

1. Wait until REST bit is set (we got the bit in within 1.5 hours)

5. Put the battery in Charge Mode

1. Set the power supply voltage as 12.6 V (4.2 *3 = 12.6v) and Current 1.3A (C/2 ratio recommended 2600/2)
2. CHG_FET is on
3. Wait until  the battery is report 100% and FC bit and VCK bit set  
4. Turn off CHG_FET
5. Put Relax mode (2hours recommended)
6. Wait until REST bit is set
7. IT status changed from 04 to 05

7. Put  the battery is again in discharging and Relax mode again.

Hello Wyatt ,

Thanks for your reply , the default which is after programmed the chemistry id , these values is updated .

I hope these default values as updated as per my chemistry id of battery whether I need to change this one or not ? Can I kept it as same.?

I have one more doubt what u meant you are charging the battery to max voltages not for your application , my battery capacity is 4.2   (3 cells are using ) 

4.3 * 2 = 12.6 v  , let me know u are telling the battery need to charge up to 12.6 voltage  , am I right ?

I will set 12.6v and 1.3 Amps in power supply and charging the battery  , my procedure is correct or not ?

One more doubt in relax mode whether I need to turn off FET_EN bit  ? Or can I keep the FET_EN bit as high in  the entire learning cycle ?

please reply  , it’s an urgent post

Hello Wyatt ,

whatever the cell is using Sony  US18650VTC5A , it’s chemistry id is 2161 is already available in BQStudio, I flashed the chemistry id , that time these values are updated. So I hope I don’t need to update these values. Can I keep these values same. 

I will make clear my questions  after the chemistry id flashing whatever the value is updated in my fuel gauge flash memory I don’t want to change for my learning cycle ??

am I right ????

Hello Mohan,

The battery has a max charge voltage of 4.2V, so your setting should be fine. It's terminate voltage is 2V though, so you may need to discharge lower than 3V in order to get 90% change in DOD.

Uploading the chem ID shouldn't change anything in your data memory that you would need to edit. It should not modify the Chg Current Threshold, Dsg Current Threshold, ,Quit Current, etc. Only the Ra table and other hidden parameters that are proprietary. 

Sincerely,

Wyatt Keller

Hello Wyatt ,

I started  learning cycle as per your instruction ,  but REST bit is not set after discharging , Could you please check the log and let me know what was the issue .

Discharging_log.rar

Hello Wyatt ,

Thanks for your reply, i have started the learning cycle  and the value is updated 0x06 in IT status .

I have few questions regarding the learning cycle . for the below line for updating L status to 0x0E , can i need to do again one more Charging with C/2 ratio- 2 hours relax - Discharge - 5 hours relax  for updating L status to 0x0E. What is the usage for this ? 

. "When the packs are deployed in the end equipment and a field update occurs, the LStatus() updates to 0x0E, which means that cell balancing has been enabled"

Hello Wyatt ,

Thanks for the reply.  IT status  0x0E will update after the charging and 2 -hour relax ,but as per the belwo document need to do again discharging  ? what  procedure is need to follow for IT status change to 0x0E . Whether the charging and relax is enough or need to discharge also ? Could you please confirm.

One more doubt  as per the below statementhow can i set the L status to  2 ??   whether it is necessary ????  whether this setting is necesaary for cycle count starts from 0. Could you please help me before exporting how can i set the L status to 2.

hello Wyatt ,

sorry i didnt get you , after updationg 0x0E , can i export .srec file from our board  hope that one is my golden image . i can use that image for my other board also.

i didn't get you how can i save the IT status as 2 before exporting the golden image . Could you please help me.

if my understanding i wrong please correct it.

Hello Wyatt ,

I need one immediate help from your side . Charging the L tstaus value changed to 0x05 , but after discharge relaxing it wont changed to 0x06.Could you please help why the issue was happened.Log_23_12_18_16.gg.csv

Hello Mohan,

It looked like from previous conversations you had completed learning, only one learning cycle is needed to create the golden image. If this is a new battery could you share the log along with the .gg from before and after?

Sincerely,

Wyatt Keller