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BQ34Z110: Help for configure the Design capacity ,Design energy Scale and Qmax cell

Part Number: BQ34Z110
Other Parts Discussed in Thread: BQSTUDIO

Hello sir,

I'm using 12V 150Ah battery.Single cell voltage is 2V.

Voltage divider : 12800mV

Q Max cell : 150Ah/6 cells = 25000mAh

Design Capacity : 150000mAh / 29000mAh = 5.17. That means rounded to 5x.

Design Energy : (12V * 150000mAh ) / 6 cells =  300000mWh

300000mWh >32767mWh.

So My design Energy scale is 10

Finally Design Energy : 300000/10 = 30000mWh

Is my whole Calculations are correct....?

  • I assume that you are working with a PbA battery. Cell manufacturers specify the pack capacity at a 1S level, so the capacity for this pack will be 150000mAh. Qmax is specified at the 1S level as well. You can use 5x scaling, but I would use 6x just to be safe.

    Qmax = 150000mAh / 6x = 25000mAh
    Design Capacity = 150000mAh /6x = 25000mAh
    Design Energy = Design Capacity x 1S cell voltage = 25000mAh x 2V = 50000mWh

    I would use the Design Energy Scale of 10x to convert the Design Energy to cWh.

    Design Energy = 50000mWh = 5000cWh
  • Thanks for u r reply.
    So my Qmax and Design capacity value are equal. (i.e 25000mAh).
    And my voltage divider value is 12000mV.
    Please tell me correct or not.
  • The 12000mV voltage divider may be close. It would be better to use bqStudio to calibrate the voltage to make it more accurate.
  • Thanks for u r reply.

    Sealed to unsealed mode.
    Voltage divider :12700mV.
    Cell terminate voltage : 1860mV.
    pack Configuration : VOLTSEL bit : 1 (for external voltage divider circuit).
    Qmax cell 0 : 150000mAh/6 cells = 25000mAh.
    Design Capacity : 150000mAh/6x scale = 25000mAh.
    Design Energy = Design Capacity x 1S cell voltage = 25000mAh x 2V = 50000mWh 50000mWh/10(scale) = 5000mWh.

    The above Configurations are ok for measuring the SOC,Remaining Capacity,Full charge Capacity,Voltage.................?
    And i have a another doubt regarding design capacity scaling..In this as u told me to use 6x scale for design capacity.For that scale value i have to multiply the value while reading.......here what my doubt is what type of parameters i have to multiply with this scale value..Can you please specify the current and capacity parameter for multiplying with that scale value...........
  • If you use current / capacity scaling, then all current and capacity parameters reported by the gauge will be scaled and you will need to multiply them by the appropriate scale factor.