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BQ25010: Will low capacity products work with BQ25010

Part Number: BQ25010
Other Parts Discussed in Thread: BQ25100, BQ25120,

Hi, I have used BQ25010RHLR and Li-ion battery (3.7~4.2V, 10400mAh).

BQ25010RHLR supports 100 or 500 mA USB charging. So the 500mA charge rate worked well, although it took quite a time to fully charge the battery.

Now, I have to work with a single cell (3.7~4.2V) Li-ion battery that has lower capacity; 2600mAh, 250mAh, and 80mAh.

I think using the 500mA charge rate with the 250mAh and 80mAh battery will cause problems.

So my questions are,

0) Can I use 100mAh charge rate with the 250mAh or 80mAh battery when using BQ25010RHLR and USB charger?

1) If not, is there an alternative IC products that I can use?

  • Hello David,

    Regardless of the battery size it is usually a good rule of thumb to charge at or below a 1C rate. This means that charging the 80mAh battery at 100mA is not recommended. In fact a number of these smaller batteries strong recommend not exceeding 0.5C charging rate.
    What do the battery datasheets recommend?

    Now the other challenge is that when the charging current gets lower so does the termination current which unless the part is designed to support small termination currents you will experience some potentially unacceptable variation in your battery termination.

    I would recommend looking at the bq25100 for the 80mAh battery. If you want to keep the additional regulated outputs that the bq25010 has you could look at the bq25120.

    Let me know if there are any other questions.
  • Hi, Ryan.

    The battery company hasn't prepared the datasheets for their 80mAh battery and 100mAh battery.

    I have this company's datasheet which describes the characteristics of a 950mAh battery. Check the above picture, please.

    This company says that the other two products (80mAh and 100mAh) are recommended to use the 0.2C discharge rate, just like the 950mAh product above.

    So the charging current should be less than

    - 950mAh product: 950 x 0.2 = 190mA

    - 100mAh product: 100 x 0.2 = 20mA

    - 80mAh product: 80 x 0.2 = 16mA

    , is it?

    Due to this reason, the bq25100 or bq25120 is suitable since this supports low charge currents, right?

  • Hello David,

    The datasheet section that you pasted above shows charging times for both 0.2C and 1.0C.

    That said if you are satisfied with charging at 0.2C for all three batteries then the bq25100 or bq25120 would be a very good choice since it can support up to the 190mA charging rate for the 950mAh battery while still able to be configured for the lower charging currents of 20mA and 16mA while still being terminate accurately at termination currents at or below 2mA.

    Let me know know if there are any other questions.