BQ40Z80: Questions about Cell Balancing

Bhavil Nagar

Part Number: BQ40Z80
Other Parts Discussed in Thread: BQSTUDIO

Hi Team,

I have a couple of questions regarding both internal and external cell balancing with BQ40Z80. I have completed a couple of learning cycles with my 4S battery and have successfully gotten my Update Status to 14 which is a must for calculating balancing time. The GG file of the same is attached below

1. What should be my UpdateStatus() for Internal balancing. The document explaining the learning cycle says that before saving the golden file I should change my UpdateStatus() to 2 which will disable the gauging. I have noticed that that after disabling the gauging, the device does not calculate cell balancing time. Basically, If I have any other value for UpdateStatus() other than 14, will the gauge not calculate the balancing time and thus disable cell balancing? The internal cell balancing works when the UpdateStatus() is 14.

2. Regarding the External balancing, I am currently using the following schematic which is present in the TRM, even the 7S part which is not necessary.

My problem with this setup is that whenever I populate the mosfets and switch from internal balancing to external balancing, the cell voltages reading gets affected. For example if all the cells are at 3.8V, some would read 1.7V but some would read greater than 5 volts. I tried the same circuit on two boards and the results were more or less the same. In one of the boards, removing the mosfets and switching back to internal balancing would bring back the cell voltage readings back to normal. But on the other board, the cell voltage readings remain to be incorrect even after removing the mosfets and turning cell balancing off(I think this board might have been damaged).

In the forum, I have come across some posts where it is said that capacitors should be placed between the Vcx inputs and not from Vcx to ground. Is that something which would help my case? If not, have you guys come across any similar case, and have any tips for me? Hoping to hear from your team soon.

40z80_ls14.gg.csv

over 1 year ago

0 Anthony over 1 year ago

TI__Mastermind 28480 points

Hi Bhavil,

Bhavil Nagar said:
What should be my UpdateStatus() for Internal balancing. The document explaining the learning cycle says that before saving the golden file I should change my UpdateStatus() to 2 which will disable the gauging. I have noticed that that after disabling the gauging, the device does not calculate cell balancing time. Basically, If I have any other value for UpdateStatus() other than 14, will the gauge not calculate the balancing time and thus disable cell balancing? The internal cell balancing works when the UpdateStatus() is 14.

I believe that this is correct. LStatus should be 0x0E or 14 before cell balancing is implemented.

Bhavil Nagar said:
Regarding the External balancing, I am currently using the following schematic which is present in the TRM, even the 7S part which is not necessary.

Regarding the capacitors, I believe they should be implemented between the VCx inputs. Below is the bq40z80EVM where they are configured in this orientation as well.

Please let me know if this is able to alleviate this issue.

Regards,

Anthony Baldino

0 Bhavil Nagar over 1 year ago in reply to Anthony

Intellectual 365 points

Thanks for your reply Anthony,

Anthony said:
I believe that this is correct. LStatus should be 0x0E or 14 before cell balancing is implemented.

So, even when I am sending the board to the user the "GAUGE_EN" bit should be set? Would keeping this bit high cause any hindrance to the capacity calculations?

I will get back to you regarding the external cell balancing circuit after testing it out. Is there a reason there is a disparity in the circuit provided for cell balancing in the TRM and the EVM's datasheet?

0 Bhavil Nagar over 1 year ago in reply to Bhavil Nagar

Intellectual 365 points

Hi Anthony,

I tried implementing the new setup with some changes on my PCB. Since my battery was at full capacity, I tried to discharge it, I do not have the logs but was monitoring using the graph.

Note, that the cell balancing was turned off and all of the cells are at similar voltages if measured with the help of a multimeter, but the gauge reads the voltage differently. Any idea what could be causing this?

0 Anthony over 1 year ago in reply to Bhavil Nagar

TI__Mastermind 28480 points

Hi Bhavil,

Bhavil Nagar said:
So, even when I am sending the board to the user the "GAUGE_EN" bit should be set? Would keeping this bit high cause any hindrance to the capacity calculations?

I believe that at the end of the learning cycle, I believe that ITEN should be cleared by changing the Update Status to 02, which should also clear the GAUGE_EN bit. When the user receives it and sends the GAUGE_EN command, this should set both the ITEN and GAUGE_EN bits. Once the user completes another discharge-relax-charge-relax cycle, the update status should change to 0E since a field Qmax update should have occurred.

Bhavil Nagar said:
Note, that the cell balancing was turned off and all of the cells are at similar voltages if measured with the help of a multimeter, but the gauge reads the voltage differently. Any idea what could be causing this?

Can you please tell me how different the voltages being reported from the multimeter are compared to the gauge? The gauge has a voltage calibration function that can be implemented if there are different voltages being reported.

Regards,

Anthony Baldino

0 Bhavil Nagar over 1 year ago in reply to Anthony

Intellectual 365 points

The voltages on the cell right now are 4059,4057,4058,4057. The following are the voltages I read between

Gnd and VC1 2206

VC1 and VC2 8293

VC2 and VC3 0010

VC3 and VC4 5663

0 Anthony over 1 year ago in reply to Bhavil Nagar

TI__Mastermind 28480 points

Hi Bhavil,

That seems like an extreme difference from the gauge and the multimeter. Is it possible to share a quick log from bqStudio of the gauge so we can take a deeper look?

Also, if you would like to share your schematic of this PCB we can take a look at that as well.

Regards,

Anthony Baldino

0 Bhavil Nagar over 1 year ago in reply to Anthony

Intellectual 365 points

Hi Anthony,

Sorry for the delay in getting back to you, I will send you the logs by the end of the day. I have sent you a friend request, please accept it and I will share you the schematic via a private message

0 Bhavil Nagar over 1 year ago in reply to Anthony

Intellectual 365 points

Hi Anthony please find a couple of log files below, the stable one was done on another BMS to show a reference while the unstable one was the BMS about which I posted originally about.

Stable log file
4530.4s_1p_stable.log

Unstable log file

Fullscreen 8244.4s_1p_unstable.log Download

Mon May 06 17:04:12 IST 2024

Device Version Info = 4800_0_04
BQZ Device Name = bq40z80
BQZ Firmware Version = V0_04_BLD5

Design Capacity = 4400
Design Voltage = 14400
Specification Info = 0x0031
Manufacturer Date = 1980-1-1
Serial Number = 0x0001
Manufacturer Name = Texas Instruments
Device Name = bq40z80
Device Chemistry = LION

Sample,DateTime,ElapsedTime,ManufAccess,RemCapAlarm,RemTimeAlarm,BattMode,@Rate(@),@TimeFull,@TimeEmpty,@RateOK,Temperature,Voltage,Current,AvgCurr,MaxErr,RSOC,ASOC,RemCap,FullChgCap,RunTimeEmty,AvgTimeEmty,AvgTimeFull,ChgCurr,ChgVolt,BattStat,CycleCnt,MaxTurboPwr,SusTurboPwr,MaxTurboCurr,SusTurboCurr,SoH,OpStatA,OpStatB,TempRange,ChgStat,GaugeStat,ITStat,MfgStat,SafetyAlertAB,SafetyStatAB,SafetyAlertCD,SafetyStatCD,PFAlertAB,PFStatAB,PFAlertCD,PFStatCD,CellVolt1,CellVolt2,CellVolt3,CellVolt4,CellVolt5,CellVolt6,CellVolt7,vBAT,vPACK,CellCurr1,CellCurr2,CellCurr3,CellCurr4,CellCurr5,CellCurr6,CellCurr7,CellPower1,CellPower2,CellPower3,CellPower4,CellPower5,CellPower6,CellPower7,Power,AvgPow,IntTemp,TS1Temp,TS2Temp,TS3Temp,TS4Temp,CellTemp,FETTemp,GaugeTemp,FltRemQ,FltRemE,FltFullChgQ,FltFullChgE,NoLoadRemCap,TrueRemQ,TrueRemE,InitialQ,InitialE,TrueFullChgQ,TrueFullChgE,T_sim,T_ambient,RaScale1,RaScale2,RaScale3,RaScale4,RaScale5,RaScale6,RaScale7,CompRes1,CompRes2,CompRes3,CompRes4,CompRes5,CompRes6,CompRes7,PackGrid,LStatus,CellGrid1,CellGrid2,CellGrid3,CellGrid4,CellGrid5,CellGrid6,CellGrid7,StateTime,DOD0_1,DOD0_2,DOD0_3,DOD0_4,DOD0_5,DOD0_6,DOD0_7,DOD0 Passed Q,DOD0 Passed E,DOD0 Time,DODEOC_1,DODEOC_2,DODEOC_3,DODEOC_4,DODEOC_5,DODEOC_6,DODEOC_7,QMax1,QMax2,QMax3,QMax4,QMax5,QMax6,QMax7,QMaxDOD0_1,QMaxDOD0_2,QMaxDOD0_3,QMaxDOD0_4,QMaxDOD0_5,QMaxDOD0_6,QMaxDOD0_7,QMaxPassedQ,QMaxTime,Tk,Ta,RawDOD_1,RawDOD_2,RawDOD_3,RawDOD_4,RawDOD_5,RawDOD_6,RawDOD_7,CBTime1,CBTime2,CBTime3,CBTime4,CBTime5,CBTime6,CBTime7,CBDOD_1,CBDOD_2,CBDOD_3,CBDOD_4,CBDOD_5,CBDOD_6,CBDOD_7,CBTotalDODChg,SOH_FC_Q,SOH_FC_E,LogRowTime(ms),LogStatus
1,2024-05-06 17:04:17,4.007,0x6D80,300,10,0x6001,0,65535,65535,0,40.1,3844,-18299,-3641,1,0,0,0,1959,0,0,65535,0,0,0x4BD0,18,-3823,-3823,-3641,-3641,85,0x6D80,0x0000,0x20,0x0011,0x65,0x0014,0x0208,0x0030,0x0081,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,3663,0,142,33,0,0,0,11767,14541,-18392,-18889,-18255,-18497,0,0,0,-6737,0,-259,-61,0,0,0,-7129,-1413,35.3,40.1,39.9,-273.2,-273.2,40.1,39.9,40.1,-24,-23,1959,3067,-20,-25,-24,1959,3067,1959,3067,39.8,39.7,1000,1000,1000,1000,0,0,0,0,0,0,0,0,0,0,5,14,5,15,15,15,0,0,0,51,8768,16384,16384,16384,0,0,0,25,24,0,1071,912,1664,1872,0,0,0,4169,4090,4186,4244,3600,3600,3600,0,0,0,0,0,0,0,25,0,0.85,245,8768,16384,16384,16384,0,0,0,65535,65535,29812,0,0,0,0,8768,16384,16384,16384,0,0,0,16384,3744,5678,1132,SUCCESS
2,2024-05-06 17:04:21,8.015,0x6D80,300,10,0x6001,0,65535,65535,0,40.0,3798,-15846,-7269,1,0,0,0,1959,0,0,65535,0,0,0x4BD0,18,-7632,-7632,-7269,-7269,85,0x6D80,0x0000,0x20,0x0011,0x65,0x0014,0x0208,0x0000,0x00F1,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,3718,0,142,32,0,0,0,11766,14541,-7014,-5301,-6116,-4071,0,0,0,-2608,0,-87,-13,0,0,0,-6687,-2789,35.4,40.0,39.8,-273.2,-273.2,40.0,39.8,40.0,-44,-44,1959,3067,-41,-44,-44,1959,3067,1959,3067,39.8,39.7,1000,1000,1000,1000,0,0,0,0,0,0,0,0,0,0,5,14,5,15,15,15,0,0,0,55,8768,16384,16384,16384,0,0,0,44,44,0,1071,912,1664,1872,0,0,0,4169,4090,4186,4244,3600,3600,3600,0,0,0,0,0,0,0,44,0,0.85,245,8768,16384,16384,16384,0,0,0,65535,65535,29812,0,0,0,0,8768,16384,16384,16384,0,0,0,16384,3744,5678,1157,SUCCESS
3,2024-05-06 17:04:25,12.026,0x6D80,300,10,0x6001,0,65535,65535,0,40.0,3819,-17575,-7627,1,0,0,0,1959,0,0,65535,0,0,0x4BD0,18,-8008,-8008,-7627,-7627,85,0x6D80,0x0000,0x20,0x0011,0x65,0x0014,0x0208,0x0000,0x00F1,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,3641,0,142,32,0,0,0,11767,14545,-22263,-22130,-21703,-21689,0,0,0,-8106,0,-308,-69,0,0,0,-8512,-2938,35.3,40.0,39.8,-273.2,-273.2,40.0,39.8,40.0,-55,-55,1959,3067,-51,-57,-57,1959,3067,1959,3067,39.8,39.7,1000,1000,1000,1000,0,0,0,0,0,0,0,0,0,0,5,14,5,15,15,15,0,0,0,59,8768,16384,16384,16384,0,0,0,57,57,0,1071,912,1664,1872,0,0,0,4169,4090,4186,4244,3600,3600,3600,0,0,0,0,0,0,0,57,0,0.85,245,8768,16384,16384,16384,0,0,0,65535,65535,29812,0,0,0,0,8768,16384,16384,16384,0,0,0,16384,3744,5678,1132,SUCCESS
4,2024-05-06 17:04:29,16.034,0x6D80,300,10,0x6001,0,65535,65535,0,40.0,3947,-591,-9616,1,0,0,0,1959,0,0,65535,0,0,0x4BD0,18,-10737,-10736,-10226,-10225,85,0x6D80,0x0000,0x20,0x0011,0x65,0x0014,0x0208,0x4000,0x00B1,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,3771,0,142,32,0,0,0,11767,14543,-695,-619,-593,-639,0,0,0,-262,0,-8,-2,0,0,0,-301,-3698,35.4,40.0,39.7,-273.2,-273.2,40.0,39.7,40.0,-69,-70,1959,3067,-69,-69,-70,1959,3067,1959,3067,39.8,39.7,1000,1000,1000,1000,0,0,0,0,0,0,0,0,0,0,5,14,5,15,15,15,0,0,0,63,8768,16384,16384,16384,0,0,0,69,70,0,1071,912,1664,1872,0,0,0,4169,4090,4186,4244,3600,3600,3600,0,0,0,0,0,0,0,69,0,0.85,245,8768,16384,16384,16384,0,0,0,65535,65535,29812,0,0,0,0,8768,16384,16384,16384,0,0,0,16384,3744,5678,1171,SUCCESS
5,2024-05-06 17:04:33,20.041,0x6D80,300,10,0x6001,0,65535,65535,0,39.9,3940,-498,-7464,1,0,0,0,1959,0,0,65535,0,0,0x4BD0,18,-10737,-10736,-10226,-10225,85,0x6D80,0x0000,0x20,0x0011,0x65,0x0014,0x0208,0x0000,0x40B1,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,3766,0,142,32,0,0,0,11767,14534,-395,-382,-361,-605,0,0,0,-149,0,-5,-2,0,0,0,-183,-2872,35.4,39.9,39.7,-273.2,-273.2,39.9,39.7,39.9,-70,-71,1959,3067,-70,-70,-71,1959,3067,1959,3067,39.8,39.7,1000,1000,1000,1000,0,0,0,0,0,0,0,0,0,0,5,14,5,15,15,15,0,0,0,67,8768,16384,16384,16384,0,0,0,70,71,0,1071,912,1664,1872,0,0,0,4169,4090,4186,4244,3600,3600,3600,0,0,0,0,0,0,0,70,0,0.85,245,8768,16384,16384,16384,0,0,0,65535,65535,29812,0,0,0,0,8768,16384,16384,16384,0,0,0,16384,3744,5678,1148,SUCCESS
6,2024-05-06 17:04:37,24.056,0x6D80,300,10,0x6001,0,65535,65535,0,39.9,3906,-1942,-6751,1,0,0,0,1959,0,0,65535,0,0,0x4BD0,18,-10737,-10736,-10226,-10225,85,0x6D80,0x0000,0x20,0x0011,0x65,0x0014,0x0208,0x4000,0x00F1,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,3669,0,142,32,0,0,0,11767,14528,-13623,-13470,-2961,-2893,0,0,0,-4998,0,-42,-9,0,0,0,-2288,-2601,35.4,40.0,39.7,-273.2,-273.2,39.9,39.7,39.9,-77,-78,1959,3067,-75,-77,-78,1959,3067,1959,3067,39.8,39.7,1000,1000,1000,1000,0,0,0,0,0,0,0,0,0,0,5,14,5,15,15,15,0,0,0,71,8768,16384,16384,16384,0,0,0,77,78,0,1071,912,1664,1872,0,0,0,4169,4090,4186,4244,3600,3600,3600,0,0,0,0,0,0,0,77,0,0.85,245,8768,16384,16384,16384,0,0,0,65535,65535,29812,0,0,0,0,8768,16384,16384,16384,0,0,0,16384,3744,5678,1164,SUCCESS
7,2024-05-06 17:04:41,28.065,0x6D80,300,10,0x6001,0,65535,65535,0,40.0,3914,-641,-5871,1,0,0,0,1959,0,0,65535,0,0,0x4BD0,18,-10737,-10736,-10226,-10225,85,0x6D80,0x0000,0x20,0x0011,0x65,0x0014,0x0208,0x4000,0x00B1,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,3740,0,142,32,0,0,0,11766,14540,-654,-659,-657,-661,0,0,0,-245,0,-9,-2,0,0,0,-251,-2265,35.4,40.0,39.9,-273.2,-273.2,40.0,39.7,40.0,-79,-80,1959,3067,-79,-79,-80,1959,3067,1959,3067,39.8,39.7,1000,1000,1000,1000,0,0,0,0,0,0,0,0,0,0,5,14,5,15,15,15,0,0,0,75,8768,16384,16384,16384,0,0,0,79,80,0,1071,912,1664,1872,0,0,0,4169,4090,4186,4244,3600,3600,3600,0,0,0,0,0,0,0,79,0,0.85,245,8768,16384,16384,16384,0,0,0,65535,65535,29812,0,0,0,0,8768,16384,16384,16384,0,0,0,16384,3744,5678,1124,SUCCESS
8,2024-05-06 17:04:45,32.075,0x6D80,300,10,0x6001,0,65535,65535,0,40.0,3915,-1449,-5190,1,0,0,0,1959,0,0,65535,0,0,0x4BD0,18,-10737,-10736,-10226,-10225,85,0x6D80,0x0000,0x20,0x0011,0x65,0x0014,0x0208,0x4000,0x00F1,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,3700,0,141,32,0,0,0,11767,14538,-7785,-5687,-234,-216,0,0,0,-2880,0,-3,-1,0,0,0,-774,-2003,35.5,40.0,39.7,-273.2,-273.2,40.0,39.7,40.0,-82,-84,1959,3067,-82,-82,-84,1959,3067,1959,3067,39.8,39.7,1000,1000,1000,1000,0,0,0,0,0,0,0,0,0,0,5,14,5,15,15,15,0,0,0,79,8768,16384,16384,16384,0,0,0,82,84,0,1071,912,1664,1872,0,0,0,4169,4090,4186,4244,3600,3600,3600,0,0,0,0,0,0,0,82,0,0.85,245,8768,16384,16384,16384,0,0,0,65535,65535,29812,0,0,0,0,8768,16384,16384,16384,0,0,0,16384,3744,5678,1144,SUCCESS
9,2024-05-06 17:04:49,36.081,0x6D80,300,10,0x6001,0,65535,65535,0,40.1,3854,-9634,-5106,1,0,0,0,1959,0,0,65535,0,0,0x4BD0,18,-10737,-10736,-10226,-10225,85,0x6D80,0x0000,0x20,0x0011,0x65,0x0014,0x0208,0x0000,0x00B1,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,3679,0,141,32,0,0,0,11767,14540,-10992,-11001,-10936,-10941,0,0,0,-4044,0,-154,-35,0,0,0,-4195,-1972,35.4,40.1,39.9,-273.2,-273.2,40.1,39.9,40.1,-89,-91,1959,3067,-87,-90,-92,1959,3067,1959,3067,39.8,39.7,1000,1000,1000,1000,0,0,0,0,0,0,0,0,0,0,5,14,5,15,15,15,0,0,0,83,8768,16384,16384,16384,0,0,0,90,92,0,1071,912,1664,1872,0,0,0,4169,4090,4186,4244,3600,3600,3600,0,0,0,0,0,0,0,90,0,0.85,245,8768,16384,16384,16384,0,0,0,65535,65535,29812,0,0,0,0,8768,16384,16384,16384,0,0,0,16384,3744,5678,1154,SUCCESS
10,2024-05-06 17:04:53,40.092,0x6D80,300,10,0x6001,0,65535,65535,0,40.1,3889,-6131,-5805,1,0,0,0,1959,0,0,65535,0,0,0x4BD0,18,-10737,-10736,-10226,-10225,85,0x6D80,0x0000,0x20,0x0011,0x65,0x0014,0x0208,0x0000,0x00F1,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,3671,0,142,33,0,0,0,11766,14541,-11538,-11542,-11491,-11534,0,0,0,-4236,0,-163,-38,0,0,0,-3240,-2242,35.5,40.0,39.8,-273.2,-273.2,40.0,39.9,40.0,-98,-100,1959,3067,-96,-99,-101,1959,3067,1959,3067,39.8,39.7,1000,1000,1000,1000,0,0,0,0,0,0,0,0,0,0,5,14,5,15,15,15,0,0,0,87,8768,16384,16384,16384,0,0,0,99,101,0,1071,912,1664,1872,0,0,0,4169,4090,4186,4244,3600,3600,3600,0,0,0,0,0,0,0,99,0,0.85,245,8768,16384,16384,16384,0,0,0,65535,65535,29812,0,0,0,0,8768,16384,16384,16384,0,0,0,16384,3744,5678,1160,SUCCESS
11,2024-05-06 17:04:57,44.095,0x6D80,300,10,0x6001,0,65535,65535,0,40.0,3903,-1809,-5093,1,0,0,0,1959,0,0,65535,0,0,0x4BD0,18,-10737,-10736,-10226,-10225,85,0x6D80,0x0000,0x20,0x0011,0x65,0x0014,0x0208,0x0000,0x40B1,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,3719,0,141,33,0,0,0,11767,14545,-2652,-902,-215,-2918,0,0,0,-986,0,-3,-10,0,0,0,-1475,-1967,35.5,40.0,39.8,-273.2,-273.2,40.0,39.8,40.0,-100,-103,1959,3067,-99,-100,-103,1959,3067,1959,3067,39.8,39.7,1000,1000,1000,1000,0,0,0,0,0,0,0,0,0,0,5,14,5,15,15,15,0,0,0,91,8768,16384,16384,16384,0,0,0,100,103,0,1071,912,1664,1872,0,0,0,4169,4090,4186,4244,3600,3600,3600,0,0,0,0,0,0,0,100,0,0.85,245,8768,16384,16384,16384,0,0,0,65535,65535,29812,0,0,0,0,8768,16384,16384,16384,0,0,0,16384,3744,5678,1125,SUCCESS
12,2024-05-06 17:05:01,48.097,0x6D80,300,10,0x6001,0,65535,65535,0,40.0,3882,-2680,-5174,1,0,0,0,1959,0,0,65535,0,0,0x4BD0,18,-10737,-10736,-10226,-10225,85,0x6D80,0x0000,0x20,0x0011,0x65,0x0014,0x0208,0x4000,0x00F1,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,3660,0,141,32,0,0,0,11766,14543,-12680,-12569,-12606,-12709,0,0,0,-4641,0,-178,-41,0,0,0,-3216,-1999,35.5,40.0,39.7,-273.2,-273.2,40.0,39.7,40.0,-108,-111,1959,3067,-105,-108,-111,1959,3067,1959,3067,39.8,39.7,1000,1000,1000,1000,0,0,0,0,0,0,0,0,0,0,5,14,5,15,15,15,0,0,0,95,8768,16384,16384,16384,0,0,0,108,111,0,1071,912,1664,1872,0,0,0,4169,4090,4186,4244,3600,3600,3600,0,0,0,0,0,0,0,108,0,0.85,245,8768,16384,16384,16384,0,0,0,65535,65535,29812,0,0,0,0,8768,16384,16384,16384,0,0,0,16384,3744,5678,1122,SUCCESS
13,2024-05-06 17:05:05,52.107,0x6D80,300,10,0x6001,0,65535,65535,0,40.1,3898,-1208,-4520,1,0,0,0,1959,0,0,65535,0,0,0x4BD0,18,-10737,-10736,-10226,-10225,85,0x6D80,0x0000,0x20,0x0011,0x65,0x0014,0x0208,0x0000,0x40B1,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,3725,0,141,33,0,0,0,11767,14546,-973,-964,-953,-942,0,0,0,-362,0,-13,-3,0,0,0,-423,-1747,35.5,40.1,39.7,-273.2,-273.2,40.1,39.8,40.1,-109,-112,1959,3067,-108,-109,-112,1959,3067,1959,3067,39.8,39.7,1000,1000,1000,1000,0,0,0,0,0,0,0,0,0,0,5,14,5,15,15,15,0,0,0,99,8768,16384,16384,16384,0,0,0,109,112,0,1071,912,1664,1872,0,0,0,4169,4090,4186,4244,3600,3600,3600,0,0,0,0,0,0,0,109,0,0.85,245,8768,16384,16384,16384,0,0,0,65535,65535,29812,0,0,0,0,8768,16384,16384,16384,0,0,0,16384,3744,5678,1142,SUCCESS
14,2024-05-06 17:05:09,56.109,0x6D80,300,10,0x6001,0,65535,65535,0,40.0,3897,-552,-3600,1,0,0,0,1959,0,0,65535,0,0,0x4BD0,18,-10737,-10736,-10226,-10225,85,0x6D80,0x0000,0x20,0x0011,0x65,0x0014,0x0208,0x0000,0x40B1,0x0000,0x0000,0x0000,0x0000,0x0000,0x0000,3724,0,141,33,0,0,0,11766,14524,-532,-544,-547,-523,0,0,0,-198,0,-8,-2,0,0,0,-207,-1392,35.5,40.1,39.8,-273.2,-273.2,40.1,39.8,40.1,-109,-112,1959,3067,-109,-109,-112,1959,3067,1959,3067,39.8,39.7,1000,1000,1000,1000,0,0,0,0,0,0,0,0,0,0,5,14,5,15,15,15,0,0,0,103,8768,16384,16384,16384,0,0,0,109,112,0,1071,912,1664,1872,0,0,0,4169,4090,4186,4244,3600,3600,3600,0,0,0,0,0,0,0,109,0,0.85,245,8768,16384,16384,16384,0,0,0,65535,65535,29812,0,0,0,0,8768,16384,16384,16384,0,0,0,16384,3744,5678,1171,SUCCESS
15,2024-05-06 17:05:13,60.123,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,2646,ERROR : Please check E:\ti\log files\4s_1p_unstable.log.err
16,2024-05-06 17:05:18,65.231,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,2626,ERROR : Please check E:\ti\log files\4s_1p_unstable.log.err
17,2024-05-06 17:05:26,73.424,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,2609,ERROR : Please check E:\ti\log files\4s_1p_unstable.log.err
18,2024-05-06 17:05:34,81.594,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,2663,ERROR : Please check E:\ti\log files\4s_1p_unstable.log.err

The device was at rest and no current was being drawn from the BMS, but the unstable log file reports a negative fluctuating current. I am starting to think that the IC itself must have gotten damaged, but I am still looking for a reason/source behind it.

+1 Anthony over 1 year ago in reply to Bhavil Nagar

TI__Mastermind 28480 points

Hi Bhavil,

I have accepted your friend request, please send the schematic there so we can take a deeper look into this issue.

Regards,

Anthony Baldino

Power management

Power management forum

BQ40Z80: Questions about Cell Balancing