{
  "ticketNumber" : "886080",
  "reporterName" : "Maxim Fiodorov",
  "rankPoints" : "70",
  "resolutionStatus" : "TI Thinks Resolved",
  "ticketName" : "BQ40Z80: 7th cell calibration problem.",
  "rankName" : "Prodigy",
  "replies" : " 9",
  "views" : " 91",
  "queryText" : "Part Number: BQ40Z80 Hi everyone. I have a problem with cell calibration by battery management studio 1.3.86. I set each of 7 cells to 4V on resistors voltage divider. I eter the values for calibration (see attached picture). But I always get 7th cell near 3940mV ad not near 4000mV. All other cells are near 4000mV. Only if I manually adjust VC7 Sense Gain I achieve desired 4000mV at 7th cell. Does anyone had the same problem with calibration by battery management studio 1.3.86.??? Is there any solution to this? I attache 2 gg files with manual and battery studio calibration. bq studio calibration.gg.csv manual calibration.gg.csv",
  "partNumber" : " BQ40Z80",
  "allResponseList" : [ {
    "contentId" : "3277767",
    "userName" : "Kang Kang",
    "rankPoints" : "17055",
    "rankName" : "Genius",
    "date" : "Mar 6, 2020 3:07 AM",
    "userId" : "3528441",
    "content" : "Hello Maxim I'm assigning this to device expert. Expecta response within 2 days."
  }, {
    "contentId" : "3279217",
    "userName" : "Maxim Fiodorov",
    "rankPoints" : "70",
    "rankName" : "Prodigy",
    "date" : "Mar 8, 2020 6:53 AM",
    "userId" : "4479536",
    "content" : "I forgot to mention when I adjust manually VC7 Sense Gain the BAT pin voltage get adjusted correspondingly but it still inside 1% battery voltage error range. I get the same phenomenon on my design and on evaluation board."
  }, {
    "contentId" : "3283550",
    "userName" : "Andy Liu (BMS)",
    "rankPoints" : "42410",
    "rankName" : "Mastermind",
    "date" : "Mar 11, 2020 10:18 PM",
    "userId" : "1864278",
    "content" : "The Cell 7 voltage is handled differently from the voltage of other cells. Let me try my EVM and see if there is a way to help you."
  }, {
    "contentId" : "3287665",
    "userName" : "Kang Kang",
    "rankPoints" : "17055",
    "rankName" : "Genius",
    "date" : "Mar 16, 2020 8:53 PM",
    "userId" : "3528441",
    "content" : "Please try on the test version (1.3.100), I believe this issue should be resolved. Thanks!"
  }, {
    "contentId" : "3293422",
    "userName" : "Maxim Fiodorov",
    "rankPoints" : "70",
    "rankName" : "Prodigy",
    "date" : "Mar 22, 2020 1:52 PM",
    "userId" : "4479536",
    "content" : "I have tried 1.3.100 version of bq Studio. The problem still exist."
  }, {
    "contentId" : "3302415",
    "userName" : "Andy Liu (BMS)",
    "rankPoints" : "42410",
    "rankName" : "Mastermind",
    "date" : "Mar 31, 2020 5:42 PM",
    "userId" : "1864278",
    "content" : "Hi Maxim, I guess what you try is to follow the steps in Section 2.2 of the following app note and see if you can have better calibration results. <secret URL>/lit/an/slua868/slua868.pdf Andy"
  }, {
    "contentId" : "3313090",
    "userName" : "Maxim Fiodorov",
    "rankPoints" : "70",
    "rankName" : "Prodigy",
    "date" : "Apr 12, 2020 12:51 PM",
    "userId" : "4479536",
    "content" : "slua868.pdf describe how to calculate the calibration coefficients. I am doing it myself to correct wrong calibration by Battery Management Studio program. My problem is the wrong calibration by Battery Management Studio."
  }, {
    "contentId" : "3322042",
    "userName" : "Andy Liu (BMS)",
    "rankPoints" : "42410",
    "rankName" : "Mastermind",
    "date" : "Apr 20, 2020 10:28 PM",
    "userId" : "1864278",
    "content" : "I will report this issue to my software team so that they can double-check if it is necessary to update their existing code. Andy"
  }, {
    "contentId" : "3323099",
    "userName" : "Shirish",
    "rankPoints" : "2420",
    "rankName" : "Intellectual",
    "date" : "Apr 21, 2020 3:50 PM",
    "userId" : "28063",
    "content" : "Do you get the same result in bqStudio if you uncheck \"Calibrate Pack Voltage\"?"
  } ],
  "tags" : [ "/support/power-management/f/196/tags/bq40z80" ],
  "fourmType" : "TI"
}