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BQ40Z80: Selection and use of different ICs

Part Number: BQ40Z80
Other Parts Discussed in Thread: BQ76907, BQ25756E, EV2400, BQSTUDIO, BQ41Z90

Tool/software:

Hello TI team,

Recently I used your BQ25756E chip to build a lithium battery charging circuit, I want to add a battery equalization module on the basis of this circuit to make the battery in the charging process to achieve the balance of the charging function. Currently I have noticed two chips:BQ40z80 and BQ76907, now I have the following questions.

1. Since I have less experience in digital programming, I would like to ask which one of these two chips can make it easier (e.g. without programming but using default settings) to equalize the battery during charging?

2. Can these two chips be directly connected to bqstudio via EV2400 for setup without the need of an MCU chip and peripheral chips?

3. Can you offer a better alternative? Currently I have 2-6 rechargeable batteries.

Thanks in advance!

  • Hello,

    For some clarification when you say "battery equalization module" are you refering to active cell balancing, cell protection and etc? Below I attached some documentation for active cell balancing and cell protector modules.

    1-Both of these components have cell balancing features, and depending on your cell chemistry you could use the default setting for most application however we still heavily recommend updating it for your system for both IC's regradles. However I've have been told that the BQ76907 is an slightly easier to program but both are similar in programming regardless.

    2-No MCU and peripheral chips are needed to configure the two chips however for the BQ76907 the EV2400/debugger is on board and the BQ40z80 would need the purchase of a EV2400 

    3-I would lead towards the new battery gauge BQ41Z90, it would be the same programming steps but has a lot of new integrated features and is the new benchmark battery gauge. 

    Active cell balacning, *most applications don't need this feature and it adds complexity to the system
    https://www.ti.com/lit/an/slyt322/slyt322.pdf?ts=1741883733331&ref_url=https%253A%252F%252Fwww.google.com%252F

    Cell protectors:
    https://www.ti.com/battery-management/protectors/overview.html


    Thank you,
    Alan

  • Hello,

    Thanks for your reply!

    For some clarification when you say "battery equalization module" are you refering to active cell balancing, cell protection and etc?

    Sorry for some lack of clarity, in this case it means active/passive cell balancing. For other protection features I don't really need it at the moment.I also have the following question at the moment:

    1. Will the ICs mentioned in previous posts (e.g. BQ41z90) affect the normal operation of the BQ25756E chip?

    2. If I do cell balancing during battery charging, do I connect the battery charging connector to the charging circuit (BQ25756E) and the battery balancing connector to the balancing charging circuit (e.g. BQ41z90)? If so, since I only have one EV2400, what is the order in which I program the two chips with bqstudio? Currently I have to program the BQ25756E after powering up the chip, can the BQ41z90 be programmed with registers before powering up? Or do I have to program the BQ25756E after powering up the chip, and the BQ41z90 before powering up the chip, or do I have to write the registers after powering up the two chips?

    3.The chips I found with cell balancing function basically need to be controlled by digital programming, I would like to ask TI has ICs that do not need digital programming but mainly realize cell balancing?

    Thanks in advance!