BQ34Z100-G1: How to set the number of strings?

Luo XiuFeng

Part Number: BQ34Z100-G1
Other Parts Discussed in Thread: BQSTUDIO

Dear Technicians:

My product is 48v16ah. After setting the voltage divider network (VOLSET set) voltage divider to set 58800mv, the voltage read by bq software is only about 42v, and the actual battery pack voltage is 47v.

     1. I have entered 47v in the calibration voltage interface, prompting me to exceed the voltage range. How to solve it? Can I manually adjust the value of the Voltage Divider to calibrate to the actual voltage?
    2, my battery pack is 14 strings, is the Number of Series Cells set to 14?
    3. Does Design Capacity mean single or single string, or the capacity of the entire battery pack?
    4. Does Design Energy mean a single or a single string, or the energy of the entire battery pack?
    5. Is Number of Series Cells in multiples with certain parameters? such as?

over 6 years ago

0 Bryan Kahler over 6 years ago

TI__Mastermind 25955 points

Hi XiuFeng,

Thank you for posting to engineer 2 engineer (e2e).

1. If you're having an issue with bqStudio, please ensure that you're updated to the latest version (bqstudiotest), found here: www.ti.com/.../bqstudio. If the calibration screen is not working, please modify the voltage divider parameter in data memory manually. Please refer to this video: training.ti.com/bq34z100-g1-voltage-calibration

The video describes how voltage divider is calculated and shows you how to modify the voltage divider value manually.

2. If the pack voltage is ~48V, and the per cell voltage is ~3.4, then yes, 14 should be the series cells value.
3. The design capacity is the capacity of the cell * the number of parallel cells.
4. Design energy is the design capacity * the voltage of 1 cell.
5. The device operates on a per cell basis. Pack voltage is measured and divided by the number of cells in series.

Please take a screenshot and post it if the voltage calibration error persists.

Sincerely,
Bryan Kahler

0 Luo XiuFeng over 6 years ago in reply to Bryan Kahler

Intellectual 676 points

Excuse me, if my capacity is 16ah, is it 16ah * 48v equal to 786 energy?

0 Bryan Kahler over 6 years ago in reply to Luo XiuFeng

TI__Mastermind 25955 points

Hi XiuFeng,

If the capacity of your pack is 16 Ah and the single cell voltage is 3.6, the design energy = ( 16 Ah ) * ( 3.6 V ) = 57,600 mWh

This value is too large to enter into the gauge. With a design energy scale = 10, the design energy would then be 5,760 cWh

Sincerely,
Bryan Kahler

0 Luo XiuFeng over 6 years ago in reply to Bryan Kahler

Intellectual 676 points

Thank you for your reply, thank you.

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BQ34Z100-G1: How to set the number of strings?