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BQ40Z50: communication barrier

Part Number: BQ40Z50
Other Parts Discussed in Thread: BQ4050

Hello, after many attempts to communicate with the gas gauge through the battery management studio GUI , I gathered some messages and operations which worked as expected from technical reference and some which are not. I would like to have your technical support about the steps i should do in order to work properly with the device:

1) reading messages using SMB protocol works good and the answers are correct( for example pack voltage or current)


2) Led toggle works as expected

3) fet enable or chg /dsch toggle works alternately , sometimes the fets remain closed although all the enable protections are disabled

4)voltage and current calibration works fine ,the data memory registers are changed according to the input calibrated values

5)the refresh button works alternately . when it does'nt work, after i presse  "REFRESH" , the commumication with the GUI disappear and i need to restart the program and the usb connection

6) the next message appears at the error line when the communication is gone :    "not able to find a free communication adapters"

7)when starting the BMS GUI the next message appears:" The selected device is not compatible with this application ! some actions could cause the device to lose communication permanently and enter an unrecoverable state .proceed at your own risk. select ok to continue, cancel to close this application. i proceed with ok  

8) when trying to calibrate the temperature sensor(internal or external) the GUI runs into an error which says :" calibration- calculated internal temperature sensor / external sensor correction is out of range"
additionally , the sensed temperature at the auto refresh main panel is -273.2 degC

9) when entering the  program ,the chemistry button at the upper toolbar disappears when trying to import a data memory file

10) i always keep the security mode at FULL ACCESS 

11) after trying to import a deafult file, the error message writes:" Parameter not written .classname Advenced charge algorithm, subclass name cell balancing config parameter name Min RSOC for balancing written to data memory failed readback verification ( it was 80% as deafult)

  • to conclude , these are some of results of using the GUI, what do i need to do in order to work with the device as it should ?
  • the gas gauge is new from the manufacture , do i need to do some initializtion or some configuration method before i apply voltage and start to work?
  • what is the difference bewteen 4500_0_12 and 9E34_0_01 at srart menu of the GUI?

thank you very much for your help.

  • Hi Arkadi,

    I suspect that your gauge is shutting down due to voltage being below shutdown voltage. I would suggest powering up the gauge or shorting 4P and PACK+ together to keep communications on. Then you can adjust it to whatever your config is.

    The 4500_0_12 is the bq40z50 and the 9E34_0_01 is the bq4050 which is a CEDV gauge.

  • Hello batt, i connected the board in charging configuration with resistive load (without battery)  so the voltage from the power supply is applied to PACK .


  • Hi Arkady,

    I don't see how you can be in charging mode with a load resistor of 10 Ohm across pack. If you split power to PACK with the battery, then the battery voltage can drop below shutdown and cause the gauge to shutdown.

  • Hi,

    The load resistors were connected where the batteries should be (not across pack), and the power supply was connected directly to the pack.

    Its a correct connection, and we worked like this on the evaluation board.

    Please suggest any ideas for solving our problems, as described at the begging of this thread.

    Thanks,

    Arkadi

  • Hi Arkadi,

    Please use 1k resistors. In either case, that's not an accurate model of a battery. You just want to make sure that a pack load doesn't cut off your battery power.