• State Answer Suggested
  • Locked Locked
  • Replies 3 replies
  • Answers 2 answers
  • Subscribers 63 subscribers
  • Views 757 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.

How to use BQ76930EVM??

YOUNG MO SEO
Prodigy 20 points
Other Parts Discussed in Thread: BQ76930, BQ76930EVM, BQ78350

Hello,

I Bought BQ76930 in South Korea.

There is no engineer available in Korea for technical support.

So I wrote here.

I have questions about BQ76930EVM.

I want to cell balancing with the battery.(type: Li-ion, Input voltage: 4.2v, capacity: 2800mh/3200mh )

I read datasheet of BQ76930EVM.

But, I do not know BATT(-,+), PACK(-,+) purpose.

Where should I input power? BATT(-,+) is right??

Next question is setting of BQ78350.

What is the proper setting value of Cell Overvoltage, Cell Undervoltage, Overcurrent in Charge Mode,

Overcurrent in Discharge Mode, Safety Over Voltage, and Safety Uder Voltage.

Last question is seal mode.

In Battery Management Studio, I pressed the seal button, by mistake.

So I tried to switch to unseal mode.

First, pressed unseal button. and input default value.

Next, pressed unseal_full_caaess button. and input default value.

But not switched to unseal mode.

What should I do??

Thank you.

  • 0
    Mastermind 8415 points

    Hi,

    YOUNG MO SEO said:

    But, I do not know BATT(-,+), PACK(-,+) purpose.

    Where should I input power? BATT(-,+) is right??

    Batt+/- is where you would connect a power supply (to mimick a battery). In your final board, you would actually connect each cell to its respective battery terminal.

    Pack+/- is what connects your battery to the outside world. This is where you would connect your load (or your charger once you have your lithium cells connected).

    You should read the BQ76930EVM User guide for the connections:

    YOUNG MO SEO said:

    What is the proper setting value of Cell Overvoltage, Cell Undervoltage, Overcurrent in Charge Mode,

    Overcurrent in Discharge Mode, Safety Over Voltage, and Safety Uder Voltage.

    You should get all that information from the battery manufacturer. You can also look at different pages online on what the general guidelines are.

    For COV and CUV: you can probably use the default values.

    For overcurrent, it will really depend on the battery and it might be written in the speicifications. Otherwise, you should contact the manufacturer.

    YOUNG MO SEO said:
    In Battery Management Studio, I pressed the seal button, by mistake.

    Once in sealed more, the device can never return to permanent UNSEALED or FULL ACCESS mode. It is possible, however, to return to UNSEALED and then to FULL ACCESS mode temporarily (until the next reset).

    Please refer to the BQ78350 Technical Reference Manual Section 11.5 for more information.

    Regards,

    Michel

  • 0 in reply to Michel Solecki
    Prodigy 20 points

    Thank you for your answer.

    But I have some more question.

    I used 7cell battery and 30V/3A Power supply.

    So shorted (VC3 VC3), (VC7 VC8), (VC8 VC9),

    (C3, C4), (C7, C8), (C8, C9),

    and remove R28,R38,R24,R34,R23,R33,R50.

    Is that right???

    And I started Battery Management Studio.

    In battery Management Studio, gauged voltage value was right.

    So, simulator switch opened C0.

    And then power supply's gauged current was 3.11A and cc's led was on.

    So off the power supply.

    Need much current is so original?

    Impossible to do that for my power supply?

  • 0 in reply to YOUNG MO SEO
    Mastermind 8415 points

    Hi,

    YOUNG MO SEO said:

    I used 7cell battery and 30V/3A Power supply.

    So shorted (VC3 VC3), (VC7 VC8), (VC8 VC9),

    (C3, C4), (C7, C8), (C8, C9),

    and remove R28,R38,R24,R34,R23,R33,R50.

    Is that right???

    Yes that is correct, but I don't believe that you need to remove the resistors since they will see 0 voltage difference because of the short.

    YOUNG MO SEO said:

    And then power supply's gauged current was 3.11A and cc's led was on.

    So off the power supply.

    Need much current is so original?

    Impossible to do that for my power supply?

    I don't understand what you mean, but I will assume that you were trying to charge and the power supply current showed 3.11A and short circuit.

    I don't want to responsible for any damage that may be caused to your cells, so I will give general guidelines. For actual charging voltage and current that you will need, I recommend that you contact the battery manufacturer to know what the recommended values are.

    The voltage of Li-On cells is usually 3.7V for each cell (so 25.4V for 7 cells). Depending on the capacity of your cells, it is very possible that the current needed to charge at a higher voltage would exceed your power supply's rating.

    When charging, they can be usually charged over 4V, but the higher you go, the more damage you will cause to your cells. If you set the voltage at 30V, you are charging your cells at over 4.2V which will most likely damage your cells.

    There are few things that you can try:

    Set a constant current charge to limit the current provided to the cells.

    Reduce the voltage until your get a more reasonable current (so start at 25.4V and gradually increase until you reach the recommended charging current). You will have to monitor the current throughout the charging process and make sure that you do not exceed the cell voltage capacity either.

    Regards,

    Michel