• State Resolved
  • Locked Locked
  • Replies 8 replies
  • Subscribers 64 subscribers
  • Views 967 views
  • Users 0 members are here
Support feedback
Options
Options
Similar topics

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.

BQ24010: How to decide the charging current?

Arun Krishnan
Prodigy 130 points
Part Number: BQ24010
Other Parts Discussed in Thread: BQ24076, BQ24040, BQ24100

Hi, I want to use BQ24010 for my design. From the application circuit, it is noted that the Charge current output (Pin) is connected to both Battery and Load together, where as in some other battery chargers (bq24076), battery connection point and system supply output pins are different. So, if the charge current ouput is connected to both battery and output load together, how does the charging works, especially in the constant current charging mode where the load current can vary?

  • 0
    TI__Guru 72571 points
    Hello
    The BQ24010 OUT and BAT connection near battery is similar to BQ24040 device, non power path where load and battery are connected together.
    The BQ24076 is a power path device that has separate outputs for load and battery. With this type of device the load is supported first and the battery is charged with any remaining current.
  • 0 in reply to Bill Johns
    Prodigy 130 points
    Thanks for the reply

    My requirement is to give a 12V supply to charge a Li-Ion Battery of 900mAH capacity and maximum charging current of 450mA. My load will be taking a current of maximum 100mA. So whether BQ24010/BQ24040 will serve the purpose or other power path devices like BQ24076 is required?

    If power path devices are required, can you please suggest a device which will serve the above purpose?
  • 0 in reply to Arun Krishnan
    TI__Guru 72571 points

    If input voltage is 12V with charge current of 450mA a switching charger will be required.
    Update ---The BQ24040 and BQ24076 are linear chargers that will not operate at 12V. The BQ24010 will operate at 12V but is also a linear charger similar to an LD0 and will have high power dissipation if the input to output voltage is high.

    Can you provide more info on you Vin min and max, charging 1 cell right?

  • 0 in reply to Bill Johns
    Prodigy 130 points
    Hi,
    In the datasheet of BQ24010, input voltage range is given as 3-16.5 V.
    I need to charge a single cell 900mAH Li-Ion Battery with 450mA nominal charging current and Vin is 12V coming either from an AC adapter or switching power supply.
  • 0 in reply to Arun Krishnan
    TI__Guru 72571 points
    Yes the bq24010 will operate, I will update post. But this is still a problem.
    The problem with operating at 12V with input charging a 4.2V battery will be power dissipation on the device. Voltage drop input to output will be about 8.5V (cell at 3.5V) and output current of 450mA the power dissipation of almost 4W. Thermal protection will kick in and reduce current but this will make predicting charge time difficult, unit will be in thermal limit most of the charge cycle.
    Reducing charge current or input voltage will help. Switching charger would be best solution.
    The normal Vin is 12V but what is min an max, +/-5%?
  • 0 in reply to Bill Johns
    Prodigy 130 points
    Hi,

    Thanks for the info..
    My Vin will be 12V +/- 5%.. So Can you please suggest a best solution with above requirements?
  • 0 in reply to Arun Krishnan
    Prodigy 130 points
    Hi,
    Waiting for your reply
  • 0 in reply to Arun Krishnan
    TI__Guru 72571 points
    Take a look at the BQ24100 family of devices, input voltage rating is 20V and they will support single cell.
    Also see the Battery Charger Solutions web page below link.
    www.ti.com/power-management/battery-management/charger-ics/overview.html