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BQ76930: BMS Solution for E-SCOOTOR

Part Number: BQ76930
Other Parts Discussed in Thread: BQ78350, BQ34Z100-G1

Hi~

I have developed E-BIKE so far.
We developed a battery pack for 10S (42V).
And, I have developed using BQ76930, BQ78350 and BQ76220 IC.

Now I have to proceed with a new project.
If possible, I would like to develop using TI company's IC, which I used a lot. My new project is E-SCOOTOR.
This product operates at 20S (72V).

So, I am looking for a solution for 20S.
I would like to use two BQ76930 and two BQ78350s.
Also, we are going to use MCU to control CAN communication and BMS.

Here, I saw a sample using two BQ76930 and MCU to make a 20S battery protective circuit. However, it was not seen using two BQ78350s.
The reason why I want to use 2 BQ78350s is because of SOC. I want to use BQ78350 because it is very difficult to get SOC.

1. Is it possible to use two BQ78350s?
2. What would be a good way to make 20S (72V) BMS? Ask for a smart answer.
(The previously developed samples seem to be developed using LINEAR's MONITORING IC a lot. I would like to develop it as a solution from TI company.)
3. If you have a sample example of 20S BMS, please introduce it.

Thank you very much.

  • Hi Jinhyung,

    The 20S TI Reference Design is the best starting point for this project. However, using two BQ78350 devices will be very difficult - I do not think this is a good solution. Each BQ78350 needs a current sense resistor (gauging depends on voltage, current, and temperature). Each BQ78350 will not be able to communicate with each other regarding cell balancing, faults, and FET control.

    There is another reference design that uses a BQ34Z100-G1 battery gauge. This gauge can be used in combination with an MCU and can be used for any number of series cells. See https://www.ti.com/tool/TIDA-010030. This reference design also includes a CAN IC.

    The best option is to combine the 20S reference design (https://www.ti.com/tool/TIDA-01093) with the reference design using BQ34Z100-G1 (https://www.ti.com/tool/TIDA-010030).

    Best regards,

    Matt