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bq24172 charger support 4cells with 12V adaptor.

Min Yeong Kim
Prodigy 20 points
Other Parts Discussed in Thread: BQ24172, BQ24170, BQ24600, BQ76920

I am looking for Battery charger IC which can charge 4s cell Li-Po Battery with up to 3A.

I saw TI product bq24170 & bq24172 and it can support 2~4cell battery in the webpage.

From the datasheet, I understood bq24170 can only 1~3-cell.

And  as I know output voltage of bq24172 is adjustable and I thought It can be support 4-cell with adjustable output voltage.

To support 4-cell, the output voltage must at least 16.8V.

But the recommanded output voltage is just to 13.5V and there is no mention about 4cell.

So I wonder,

1. Can bq24172 support 4s cell Li-Po Battery?

2. If it can support, is it right that the value of R2 and R1 to FB port is 698K & 100K?

3. We will use 12V/5A adaptor, but I hope to use recommended DC adaptor for power efficiency.

Regards,

Mykim.

  • 0
    TI__Expert 3160 points
    The bq2417x family parts only support up to 3S charging. Please consider the bq246xx family parts for 4S charging.

    Can you give any additional project requirements so we can help your find the best charger for your application?

    Thanks!
    Rachel
  • 0 in reply to Rachel Moore
    Prodigy 20 points
    Thanks for your reply.

    We are preparing 4-cell charger with 2nd protection IC and cell balancing for li-po battery.
    And to minimize the function from micro-controller, we are looking for stand-alone type.

    So as you said, we find bq24600.

    And for cell-balancing and protection function, I found bq2920x series and bq76920.
    But I think bq76920 need data flash control by I2C communication from host.
    And I saw bq2920x series. In the description part, it support only 2-cell.
    And also I saw Parametirc part "# Series Cells : 2-4 cell ".
    So I thought there will be a way to combine this two ICs for 4-cell.

    But the more i see the datasheet, I feel it's impossible.
    Is there any method to apply this bq2920x to 4-cell?
    And I hope to find any IC to replace this if possible.

    I confuse and I wonder why it is writen like this, "# Series Cells : 2-4 cell " parametric part in webpage.

    Regards.
    Mykim.
  • 0 in reply to Min Yeong Kim
    TI__Expert 5565 points

    Min Yeong,

    The bq2920x cannot be used to balance 4 cells in series since there is no method for two bq2920x ICs to communicate to each other. Therefore, this would result in the two pairs of 2-cell batteries to not be balanced to each other.

    In the parametric search, the search parameters are grouped in three categories: single cells, 2-4 cells, and >4 cells. Since the bq2920x is a 2-cell protection IC, it falls under the 2-4 cell category.