• State Resolved
  • Locked Locked
  • Replies 5 replies
  • Subscribers 64 subscribers
  • Views 3362 views
  • Users 0 members are here
Support feedback
Options
Options
Related

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

"charging voltage" and "charging current" in BQ IC

Zhanyu Fu
Intellectual 410 points
Other Parts Discussed in Thread: BQ27541, BQ20Z45, BQ24765

Hello experts:

                        i have questions for the "charging voltage" and "charging current" defined in the BQ IC. I know the charging voltage is used to be as the one of the conditions to determine  the primary charge termination by checking Voltage=charging voltage-taper voltage.

                        Is this only usage of the charging voltage defined by the BQ IC,or is there other usage for caculation by BQ IC?

                        I have not found any caculation for the "charging current", what does the "charging current" used for? if the "charging current" is set 600mA, does it mean the current in system will be limited to maximum 600mA during charging? So does the "charging voltage"?

                        Thank you.

                         

  • 0
    TI__Genius 14985 points

    What product/gauge are you using?

  • 0 in reply to dMax
    Intellectual 410 points

    in most cases, i deal with the Li-ion Pack with BQ IC of BQ27541 and BQ20Z45, i just want to make these two variables more clearly, thank you.

  • 0 in reply to Zhanyu Fu
    TI__Intellectual 2120 points

    Hi Zhanyu,

    In summary, the ChargingCurrent( ) and ChargingVoltage( ) values are intended to be used by a smart charger system. a Host device will read these values and program an external charger, such as the bq24765, or the gas gauge IC can broadcast this data directly to the Smart Battery Standard (sbsforum.org) compliant charger.

    In some devices these values are used for checking system safety conditions, basically checking if the host/charger is doing what the gas gauge is asking or providing excessive voltages/currents.

    Best regards

    Garry

  • 0 in reply to Garry Elder
    Intellectual 410 points

    Hello Garry:

                       Thank you. I have another question: if the charging voltage is set 16V, and the charging current is set 1000mA, if it is charged with 20V and 1500mA by a charger, its actual charging charging voltage and charging current in the system are 16V and 1000mA? Or its actual charging charging voltage and charging current in the system are 20V and 1500mA?

                       Thank you.

  • 0 in reply to Zhanyu Fu
    TI__Intellectual 2120 points

    Hi Zhanyu,

      The GG cannot limit the current or voltage (unless the pre-charge function is in operation), only the charger can do that. The GG can turn off the CHG FET to stop current if the voltage and/or current exceed the safety settings but that is all.

    Best regards

    Garry