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Charging Li-Ion Battery pack using BQ24192

Nitish Dhiman
Prodigy 120 points
Other Parts Discussed in Thread: BQ24192, CC2640, BQ27531EVM, BQ27531-G1

In my current project we are using Li-Ion Battery Pack 3.7V @19800 mAH  with BQ24192 Battery Charger IC.

For charging this Battery Pack we have two Options:

  • Through USB
  • Through Power Adapter 

If we charge through Micro USB and Power Adapter what shall be the time required to Completely Charge this Battery Pack in both cases.

Moreover  can we use BQ27441  Fuel Gauge with this Battery Pack(19800 mAH) .

  • 0
    TI__Mastermind 25800 points

    Hey Nitish,

    Before I answer your question, I need some more information. 

    Are you using this device without a host, or with a host communicating through I2C?

    The type of USB port also affects the charging capability of the bq24192. This current limitation is done through the PSEL and OTG pins on the part. What did you tie those pins to? Power rail or Ground?

    By default, the charge current for the bq24192 is set to 1024mA. Are you changing this value? Are you setting a lower input limit through the ILIM pin

    To your second question, yes, that gauge should work fine. 

    Regards,

    Joel H

  • 0 in reply to Joel Hernandez II
    Prodigy 120 points

    Are you using this device without a host, or with a host communicating through I2C?

    Yes Host Communicating through I2C

    The type of USB port also affects the charging capability of the bq24192. This current limitation is done through the PSEL and OTG pins on the part. What did you tie those pins to? Power rail or Ground?

    We are using Micro USB type B and Controlling PSEL pin through Host MCU(Pulling up and  down to be controlled by MCU) so we can switch Between USB source and Power Adapter.

    OTG pin is pulled up in current design.

    By default, the charge current for the bq24192 is set to 1024mA. Are you changing this value? Are you setting a lower input limit through the ILIM pin

    Yes we are changing this value to 178 ohm resistor and setting Current limit to 3 Amp on ILIM Pin.Can Micro USB source provide this much current.

     Please Recommended way out to fast charge Battery(19800 mAH) through Micro USB. 

     

     

     

     

  • 0 in reply to Nitish Dhiman
    TI__Mastermind 25800 points

    Hey Nitish,

    So MicroUSB is a type of connector under the USB standard, not a power classification. 

    The power capability is defined under different conditions, such as USB1.0, 2.0, 3.0, and 3.1 along with Battery Charging Specification 1.2 (BC1.2). These define the current and voltage available for different types of ports. Which brings me to ports.

    There are Standard Downstream Ports (SDPs), Charging Downstream Ports (CDPs), and Dedicated Charging Ports (DCPs). Of these, in order to charge faster with your battery capacity, you would want to find a DCP. This would be something like an AC adapter or portable charger (5V/2 or 3A). Now you may also consider using a CDP, which may be available from a computer or laptop USB port (I believe these may have a lightning bolt symbol to signify higher currents), and these offer the 5V/1 or 1.5A. 

    All other USB ports would be detected as 100mA or 500mA current limited ports.

    In short, if you want more than 500mA of charge current, you want to use a DCP to give you 2A or greater of charge current and PSEL always LOW. 


    As a side note, there are two versions of the charger you are using; the bq24192 and bq24192i. In regards to this question, the 192 PSEL LOW indicates 3A current limit and 192i PSEL LOW indicates 1.5A current limit. 

    Regards,

    Joel H

  • 0 in reply to Joel Hernandez II
    Prodigy 120 points

    Hi Joel,

    The above explanation really helps.

    Going through Datasheet for BQ24192 I find 

    In default mode, the charger IC will reset REG00[7] back to 0 when input source is removed. When another
    source plugs in, the charger IC will run detection again, and update the input current limit.

    So My concern is when Battery is completely drained out and when source is plugged IN, by default charge current is limited to 100mA .until host configure Battery Charger register setting over I2C to increase Current limit.

    So My hardware architecture is like Battery Charger SW pin is connected to buck Boost regulator which power ON Host CC2640 and low power mode chip.so will default charge current 100 mA be sufficient to enable host CC2640 and increase Current limit to charge the battery during this scenario when Battery is completely drained.

         

  • 0 in reply to Nitish Dhiman
    TI__Mastermind 25800 points
    Hey Nitish,

    So the default INPUT CURRENT LIMIT for the device is not 100mA. That is based on what you set for your OTG and PSEL pins as described in Table 3 of the datasheet.

    The default CHARGE CURRENT is 2048mA on that part.

    In reference to your system architecture: I do not believe you should have a problem charging the battery AND powering your system to have host control over the charger. I only see possible issue during converter soft-start, which as a 100mA current limit to ramp the Vsys voltage up to 2.2V, before turning the converter fully on to reach Vsysmin. If your load current is too high for the CC2640, it may take a little longer than usual to power on the CC2640.

    However, system takes priority in cases of system load and battery charging. Because the battery will be drained, the charge current for the battery is limited, and the remaining input current can be used for Host power on.

    BOTTOM LINE: Your PSEL and OTG pins dictate your input current limit when a source is plugged in.

    Regards,
    Joel H
  • 0 in reply to Joel Hernandez II
    Intellectual 690 points

    Hi Joel,

    I am also doing development work on BQ27531EVM demo board (Bq27531-g1 gauge and bq24192 charger). The battery that I'm using is Panasonic NCR18500A (1900mah).

    While I'm doing the learning cycle, I observed that the charging current is only around 0.463A. I'm using USB charger connected to laptop with PSEL and OTG set to HI which will make INLIM set to 500mA limit. I want to increase the charging current to its 1.38A standard rating but I can't seem to do this.

    I tried to charge the battery using power supply connected across VBUS and GND (6V, 3A) and changed the PSEL to LOW. The INLIM bits changed to indicate 3A current limit, but the charging current never increased. How can I increase the charging current, then?

    Also, you mentioned and I also read in the datasheet that the default charge current must be 2048mA for this part. But when I read Reg2 [ICHG[5:0]], the value is 1'b011000. How does this equate to charge current in mA? What does this value mean? I'm pretty sure it's not 2048mA because my measured charging current is only around 0.463A. I  also see that there is no way for me to change these bits as it is controlled by FG's algorithm. Is my understanding correct?

    This is my first time to work on batt gauge and charger ICs so Any input is appreciated

    Thansk!!

  • 0 in reply to mrausol
    TI__Mastermind 25800 points
    Hey Nitish,

    It seems like you posted this question in a new thread. So I will refer the previous question to that post, and close this thread:

    e2e.ti.com/.../2064622

    Thanks!