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BQ4050: ChargingStatus() data sheet inconsistencies

Trevor Morgan
Prodigy 95 points
Part Number: BQ4050
Other Parts Discussed in Thread: BQ40Z50-R1, BQ40Z50

We have recently received batteries using the BQ4050 controller and I am attempting to integrate them into our hardware.

The BQ4050 technical data sheet is inconsistent regarding ChargingStatus().

  • In the description (e.g. section 2.3) 7 temperature range bits are mentioned (UT,LT,STL,RT,STH,HT,OT); these do not appear in the description of ChargingStatus (section 13.1.37).
  • The description includes voltage range bits PV,LV,MV,HV.  These do not appear to correspond to the actual cell voltages, nor to the selected ChargingCurrent() (I have set a unique value for each current).
  • The IN bit in the description is often set when charging is clearly not inhibited.
  • CCC bit is set when Configuration[CCC] is not enabled.

It appears that the ChargingStatus() description is incorrect.  What are the correct contents?

  • 0
    TI__Genius 10830 points
    hi Trevor,
    Most of our battery experts are out of the office today. We will look at your question on Monday.
  • 0 in reply to David Hien
    Prodigy 95 points

    David Hien said:
    Most of our battery experts are out of the office today. We will look at your question on Monday.

    Have your battery experts had a look at this yet?

  • 0 in reply to Trevor Morgan
    TI__Mastermind 42535 points
    Trevor,

    ChargingStatus indicates the charging region that the battery is in. It's a combination of temperature and voltage ranges as defined in chapter 4 of the TRM. Specifically look at sections 4.1-4.4. The definitions are correct.
  • 0 in reply to Batt
    Prodigy 95 points

    Batt said:
    Trevor,

    ChargingStatus indicates the charging region that the battery is in. It's a combination of temperature and voltage ranges as defined in chapter 4 of the TRM. Specifically look at sections 4.1-4.4. The definitions are correct.

    I cannot see any definitions of which bits in ChargingStatus() represent the temperature.
    From the TRM:
    13.1.37 ManufacturerAccess() 0x0055 ChargingStatus
    31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16
    RSVD RSVD RSVD RSVD RSVD RSVD RSVD RSVD
    15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
    TAPER RSVD RSVD RSVD RSVD CCC CVR CCR VCT MCHG SU IN HV MV LV PV
    and
    4.2 Charge Temperature Ranges

    Under Temp

    ChargingStatus()[UT]=1

    Low Temp

    ChargingStatus()[LT]=1

    Standard Temp Low

    ChargingStatus()[STL]=1

    Recommended Temp

    ChargingStatus()[RT]=1

    Standard Temp High

    ChargingStatus()[STH]=1

    High Temp

    ChargingStatus()[HT]=1

    Over Temp

    ChargingStatus()[OT]=1
    • Flags UT,LT,STL,RT,STH,HT and OT mentioned in section 4.2 (and elsewhere) are missing from the definition in section 13.1.37
    • IN is set when charging is not inhibited
    • CCC is set when Configuration[CCC] =0
    • Sometimes no voltage bits are set (HV,MV,LV,PV)
    • e.g. I often see ChargingStatus() = 0x000410

    Conclusion: section 13.1.37 is incorrect.

    Please let me know where I can find the definitions of the temperature bits in ChargingStatus().

  • 0 in reply to Trevor Morgan
    TI__Mastermind 42535 points

    OK. I now understand what you mean. Yes, that section for bit definitions is possibly wrong. Please refer to the bq40z50-r1 TRM section 13.1.41 for the appropriate definition.

    Section 4.2 defines temperature ranges and the image on pg 29 gives the range from UT to OT

    they will be reflected in charging status. So that definition of ranges is correct.

    The config in charging status comes from the ranges defined in DF. It also depends on how often you scan the gauge. You really don't need to scan the gauge more than once per second.

    I understand that the TRM isn't easy to read. However, the bit definitions are scattered in it. Please search if you can't find it in the appropriate section.

    But thanks for pointing out that error. We will refer this to our systems engineers to get it edited.

  • 0 in reply to Batt
    Prodigy 95 points
    The bits defined in section 13.1.41 the BQ40z50 TRM are not quite quite correct for BQ4050.
    Bits 0-12 appear to be correct (Temperature range (UT..OT), Voltage range(PV..HV) and Inhibit (IN))
    The remaining bits differ. I think the bits should be as follows:
    Bit 13: SU (guess, not actually seen)
    bit 14: MCHG (seen when ChargeCurrent() is set to maintenance current)
    bit 15: VCT (seen after charge termination)
    bit 16: TAPER (seen after charge termination)
    bits 17-19: I presume these are CCR,CVR and CCC.
    bit 23 is sometimes set during charging, but I cannot determine its purpose.