BQ27542-G1: How came to know wether received chemid is correct or not for particular battery

Hello Wyatt,

Agree with you regarding learning cycle.

Can you please tell me how can i discharge my battery to  2.0v as my FG is turning off at 2.7V?

My boards are already fabricated and i want to go with BQ27542-G1, previously we are using 12000mAh battery which is 3.0v lower cutoff voltage.

Now our customer requirement changed  and they want to go with 3000mAh battery which is having 2.0v lower cutoff.

I hope you understand what i want exactly from you

Thanks,.

Vishal kalmani

Hi Wyatt,

Thanks for your reply.

Can you please any alternative methode ?

Because around 2k boards are fabricated , this will impact huge .

Hello Wyatt,

Even though battery termination voltage is 2.0v and higher termination is 3.6v.

If i take the IVT log 3.6V to 2.8v and submitting it to GPC tool. Is the received chemid is for (3.6v to 2.8V)? 

Is that correct one ? Can we do like this ?

Hello wyatt,

As per the TRM note 

Here i have found 3000mAh battery and in our case also 3000mAh lifePo4

Can i use the same one ?

Please advise 

Thanks,

vishal kalmani

Hi Wyatt,

Thanks for the alternate part but it is not P2P.

Ok here i am attaching  images 

As per the TRM note 

Here i have found 3000mAh battery and in our case also 3000mAh lifePo4

Can i use the same one ?

I will carry out learning cycle as per your suggestion

Please advise 

Thanks,

vishal kalmani

Hello Wyatt

Thanks for your prompt response .

I will carry out and will let you know if any further questions arise

Thanks,

Vishal

Hello Vishal,

No problem, I hope you are able to get your system working well.

Sincerely,

Wyatt Keller

Hello Wyatt,

Below data are setting in gas gauge data memory section for learning cycle, Please check and provide your suggestion if anything missing/incorrect

1.Design capacity             :   3000mAh

2.Design voltage              :   3200mV

3.Charge term taper current    :   400mA(Taper current of charger)

4.Discharge current threshold   :   60mA

5.Charge current threshold     :   75mA

6.Quit current               :    40mA

7.Termination voltage         :   3000mV(2000mV given in battery data sheet)

8.Design energy              :   3000X3.2= 9600

9.Design energy scale          :   1 (in 12000mAh it is 10)

10.V at charge termination      :   3650mV

11.Charge voltage             :   3650mV

12. Qmax cell0                :   3000mAh

13. Pack configuration          :   Internal temperature set

I have question regarding the termination voltage and attaching the battery datasheet for your reference

As per learning cycle note 

Termination voltage be set minimum voltage of the battery as specified in the data sheet.

After learning  cycle completed, this value can be adjusted upwards if there is need for the gauge to report 0% higher voltage.

So my question is , i am not able to discharge less than 3V  for that only i am setting 3v instead of 2v for leaning cycle.

This will leads learning cycle fail ? if yes what is the alternate way to carry out the above successful learning cycle for BQ27542-G1?

Please consider i can not change fuel gauge.

Thanks,

Vishal kalmani （20200620 updaed ）POWEROAK-datasheet of LFP805993-3000mAh 3.2V LiFePO4 cell.pdf

Hello Vishal,

The configuration looks okay besides the termination voltage, when you run the logging cycle it needs to be the full range of the battery voltage to get the correct chemID as mentioned before.

If you are planning to go to 2V, how will the gauge be powered?

To successfully complete a learning cycle the gauge must see a 90% change in the DOD, there is no way to complete a learning cycle because the gauge will shutdown before you can cycle the battery fully.

Sincerely,

Wyatt Keller

Hello Wyatt,

Here little bit confusion , let me clear

As you suggested for chemid I would run the cycle and use gpcm tool and get chemid  instead of using what I had sent you existing chemid .

Now what I am doing , I am using existing chemid and carrying learning cycle.

The only question is if I set termination voltage as 3v and will carry learning cycle.

Termination voltage is nothing but 0% SoC  gauge will come to know right ?

I know DoD must be 90% , if I set termination voltage  then gauge must understand at 3v nothing but 100% DoD.

Please let me correct if I am going  wrong path

Thanks,

Vishal

Hello Wyatt,

Thanks for above all reply.

Now we are seeking your help on call , Please try to give your some time to carry out learning cycle.

Now we are stuck while setting the parameter in  bqstudio and please try to help and will solve the problem.

Awaiting your soonest response !!

Thanks,

Vishal kalmani

Hello wyatt,

below are the some question-

1. To carry out learning cycle i am setting all the parameter which is needed and after that successfully write and read also done.

Charging voltage parameter needed to set or not ? 

2. Is it needed to carry out learning cycle on fresh/ Blank Fuel gauge IC? Suppose if golden image loaded into one of Fuel gauge IC and wanted to use same for learning cycle ?

3. After writing parameter and chemid , without  any electric load i am seeing board discharging around 900mA and suddenly battery goes on lower cutoff ? Why ?

Above all the things carried out using LIFEPO4/3000mAH

Parallelly i did the same activity, in which board populated 12000mAh LIPO battery and FG has golden imaged. This golden carried out successfully by me with the help of andi liu.

But i have changed  all the parameter , chemid and i had attached 3000mAH LIFEPO4 battery, not seen above things in this activity.

but after changing the New FG IC this things have been observed.

It would be great if you can provide your email id  so that i can get immediate response

thanks,

Vishal kalmani

Hello Wyatt,

Above problem is solved after doing the cc and delta parameter calibration.

Here are some problem facing while learning cycle,

Did initial discharge cycle  and every operation and expected flags are clear and set.

After above step once my battery reach at 2.8V i have disconnected load and put into relax mode for 5 hrs.

Sleep bit set .

In this relax cycle i had observation some errors;

1. EV2XXX Adapter usb timeout 

2. No ack from device 

3. voltage and any other value is not sowing .

Thanks ,

vishal

Hello wyatt,

Above  problem solved after calibration.

Here are some problem facing while learning cycle,

Did an initial discharge cycle  and every operation and expected flags are clear and set.

After the above step, once my battery reaches at 2.8V,  I have disconnected the load and put it into relax mode for 5 hrs.

Sleep bit set .

In this relax cycle i had observed some errors;

1. EV2XXX Adapter usb timeout 

2. No acknowledge from device (I want why this warning is coming and what is the impact on learning cycle ).

Does it means not getting I2C data ?

3. voltage and any other value is not showing.

Thanks,

Vishal kalmani

Hello Vishal,

What were the conditions when the communication stopped? It appears the gauge has no power or there is a communication line error or bad connection. Is it occurring after a certain amount of time after the relax is started?

Sincerely,

Wyatt Keller

Hello Wyatt,

As per the fuel gauge datasheet fuel gauge will turn off below the 2.7v and I am discharging my battry to 2.8v .

As I told on above queries

1. The register bits/ flags are automatically set and clear

2. Ev2xx usb timeout

3. No Acknowledgments from device

This only error I have seen .

Wanted to know meaning of no Acknowledgments from device ?

Is that i2c line error  or something else ?

Thanks,

vishal kalmani

Hello wyatt,

Thanks for the reply.

As you know we are running learning cycle and strictly following the Learning cycle documents.

As mentioned in learning cycle documents,

1st discharge cycle ------

RUP_DIS = High 

QEN =High 

Update status=04

This operation is happening correctly.

====================================================

1st relax cycle for 5 hrs--------

Vok = Clear 

RUP_DIS = Clear within 5hrs time 

Sleep = High 

This operation is happening correctly

==================================================

Charge cycle ----------

Vok = High (At the start of charge )

RUP_DIS = Clear (to update registor table)

FC = High 

In this cycle Vok = low and RUP_DIS = high  because of this bit update status and register table not updating 

Please advice why those above two bits are not setting ?

Thanks ,

Vishal kalmani

Hi Kang ,

Thanks .

I will make sure battery will relax minimum 5 hrs.

I hope this is the only problem you have seen , please let me know if any other concern on the same ?

Thanks,

Vishal kakmani

Hi kang,

Thanks for reply .

What if i generate the golden image even though update status is not 06h?

While learning cycle all the things i mean soc , voltage ,  current etc showing correct 

Please advice 

Thanks,

Vishal

Hi kang,

Thanks for you reply.

Just wanted to clear, do you mean i have to compare Ra table which is imported .GG file before starting the learning cycle?

What if not seen any difference?

One more question,

I want to set DOD%=51%, where i can write it because in tool they given two option.

1.  start DoD.

2. End DoD.

Thanks,

Vishal kalmani 

Hi Wyatt and Kang,

Qmax update bit is not toggled and that is what Ra and Updates not gets incremented.

Can you please tell me reason? what needs be taken care in next time?

Here i am attaching the logs (.gg files )

Please have look into it.

Thanks,

Vishal F0DF.zip

Hi Wyatt ,

Thanks for the reply .

Just for your information I have carried out learning cycle succesful with 12000mAh lipo battery .
We are following the learning cycle pdf.
Trm and learning cycle document have different rules.
Can you please tell me what is the rup dis and vok bit at this stage to toggle the qmax ?
I agree with you on above point after relax of 2 hrs and update status gets 05. I had disconnect the cycle because there is no meaning to go ahead.
I am attaching which docs we are referring0827.7367.Achieving the Successful Learning Cycle (1).pdf

Hi wyatt/Kang,

I am attaching image of monitored bit which we have prepared.

The problem is Vok bit not getting clear(Highlighted in red circle) even tough relax cycle  kept for 4hrs and we don't have any control on that bit .

Now we are in critical situation and want your extended support.

Still cycle is running so that is what  i am not attaching log files.

Hi wyatt and kang can you please provide your email id ? So that communication will be faster.

Please let me know if you need any information?

Thanks,

Vishal 

Attaching image 

Hello Wyatt/Kang,

Please find the attached log and please let me know why VOK Bit was not cleared because of this only QMAX not updated and update status too.

After that there is only one one discharge and relax cycle pending.

We are in critical stage and seeking your help on immediately.

As per discussion with shashank TI representative at indian side had discussion with you and raised red flag too.

All.zip

Thanks,

Vishal 

Hello Wyatt and kang,

Can you Please reply on the above questions?

Please try to understand the timeline.

Please do needful

Thanks,

Vishal

Hello Vishal,

If you are in the flat region of the OCV the VOK wont set when expected because the gauge will not take an OCV reading for Qmax in this region. Also make sure you discharge 90% of the design capacity for the successful learning cycle.

The Achieving a successful learning cycle is written for many different gauges, you can use it as a guide but for the gauge specifics you have to refer to the TRM.

Can you share your chemID report you received from the GPCCHEM tool?

Sincerely,

Wyatt Keller

Hello Wyatt,

As per discussion with TI guy shashank  we have set fast qmax end dod  is 51%.

The chemid we are flashing is 0466 .

I had compared Ra table using .gg file some of the value got changed even though qmaxupdate is not set . Can we generate and enter 06 update status manually and start testing ?

Thanks ,

Vishal

Hello Kang ,

Below is the alternative chemid 

0417(3000mAh, Sony, LiFePo4)

Please check this one and advice.

Thanks, 

vishal

Hello kang,

I Just want to know after full charge fc bit sets and Vok bit sets.

After relaxing two hours of time vok must gets clear and update status must be 0x05.

Can you please let me know why vok bit not getting clear ?

Thanks, 

Vishal