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BQ24450: BQ24450

AIED BEBAR
Intellectual 680 points
Part Number: BQ24450
Other Parts Discussed in Thread: BQ2031, BQ25703A, BQ25703, BQ24650

HII 

 i want to use your BQ24450 for lead acid battery charger  my maximum charging voltage is 6 v and i want to charge 4 v lead acid battery .is it possible ?

and another question what is the minimum voltage i need to supply to the BQ24450 in order to charge 6v lead acid battery .

and the same question applies for the  bq2031 ??

do you have a recommendation for charger ic for lead acid batteries , my max charging voltage 6 v with current 2.15 A

I NEET TO CHARGE 4V LEAD ACID and 6v lead acid ?

  • 0
    TI__Mastermind 19195 points

    Hi Aied,

    Yes, this is possible with BQ24450. What are the voltage specifications of battery over charging cycle?

    BQ2031 has max supply voltage of 5.5V so would not work with 6V input voltage.

    Best,

  • 0 in reply to Nick Brylski
    Intellectual 680 points

    hii thanks for your reply 

    if i want to use  BQ24450 to charge a ( 6 volts lead acid battery- 3 cells is series) and my input voltage  to the BQ24450 IS 6 volts with 2 amps of current .

    is it possible to feed the  BQ24450  with 6 volts input and the bq24450 can charges the 6 volts lead acid battery or i need to step up my input voltage from 6 volts to higher voltage in order for the bq24450  to work ??

    and do have a charger with a built in boost capability  that it can take 6 volts input and boost it so i can charge ( 6 volts lead acid battery- 3 cells is series)?

    the main reason for my questions is  as you see my input voltage to the charger ic and the battery  voltage is equal to 6 volts .

  • 0 in reply to AIED BEBAR
    TI__Mastermind 19195 points

    Aied,

    You would need to step up the input voltage if you wanted to use the BQ24450. There is a minimum voltage difference between input-output that depends on which external transistor config is chosen. A better solution may be something like buck-boost charger BQ25703A. 

    Best,

  • 0 in reply to Nick Brylski
    Intellectual 680 points

    hi nick ,thanks for your help 

    1-nick my energy source for the charger works best with a load of 2.8 ohms at 6 volts output,  that mean that optimum charging current should be 2 amp or less , is there an option to set by hardware the charger current ?

    2- how do i choose the chemistry of the battery (my battery is lead acid ) can i choose the chemistry by hardware ?

    and the battery is   6 volts that means it has 3 cells of lead acid how can i set the number of cells ?

    3- i want my charger to work automatically without host inference is it possible ?

    i mean when my charging source begins to work and my lead acid battery is plugged in the charger begins charging 

    3- i will insure that my input voltage to the charger is 6 volts , and with charging current of 2 amps what are the components that i need change in the design , ?

    taking into consideration that the voltage of my lead acid battery is 6 volts

  • 0 in reply to AIED BEBAR
    TI__Mastermind 19195 points

    Hi Aied,

    1-nick my energy source for the charger works best with a load of 2.8 ohms at 6 volts output,  that mean that optimum charging current should be 2 amp or less , is there an option to set by hardware the charger current ? Yes, this is possible with our battery chargers, charging current can be set through external resistor or I2C depending on the part.

    2- how do i choose the chemistry of the battery (my battery is lead acid ) can i choose the chemistry by hardware ?and the battery is   6 volts that means it has 3 cells of lead acid how can i set the number of cells ? Battery chemistry you chose will depend on the application. Most of our battery chargers are for li-ion but we also support lead acid and other chemistry. 

    3- i want my charger to work automatically without host inference is it possible ?

    i mean when my charging source begins to work and my lead acid battery is plugged in the charger begins charging. Yes, this is possible.

    3- i will insure that my input voltage to the charger is 6 volts , and with charging current of 2 amps what are the components that i need change in the design , ?taking into consideration that the voltage of my lead acid battery is 6 volts. As stated in my last post, using BQ24450 with 6V input and 6V Vbat will not work. Look into buck-boost chargers or add a boost converter before BQ24450.

     

    Best,

  • 0 in reply to Nick Brylski
    Intellectual 680 points

    hii nick thanks for your reply 

    I asked those question for the bq25703A charger 

    my energy source for the charger works best with a load of 2.8 ohms at 6 volts output,  that mean that optimum charging current should be 2 amp or less , is there an option to set by hardware the charger current in the bq25703A?

    in the bq25703A how do i choose the chemistry of the battery (my battery is lead acid ) can i choose the chemistry by hardware ?and the battery is   6 volts that means it has 3 cells of lead acid how can i set the number of cells ?

    for the bq25703A if my input voltage to the charger is 6 volts , and my lead acid battery that I want to charge is also 6 volts , what components I need to change ?

    or is there an recommended application schematic that can work 

  • 0 in reply to AIED BEBAR
    TI__Mastermind 19195 points

    Aied,

    my energy source for the charger works best with a load of 2.8 ohms at 6 volts output,  that mean that optimum charging current should be 2 amp or less , is there an option to set by hardware the charger current in the bq25703A? Yes over i2c

    in the bq25703A how do i choose the chemistry of the battery (my battery is lead acid ) can i choose the chemistry by hardware ?and the battery is   6 volts that means it has 3 cells of lead acid how can i set the number of cells ? Battery voltage for bq25703A can also be set over i2c

    for the bq25703A if my input voltage to the charger is 6 volts , and my lead acid battery that I want to charge is also 6 volts , what components I need to change ?

    or is there an recommended application schematic that can work.You can check out the EVM, a schematic is included. http://www.ti.com/tool/BQ25703AEVM-732

     

    Hope this helps,

  • 0 in reply to Nick Brylski
    Intellectual 680 points

    hii

    nick thanks for your reply 

    what I meant in my first question is there an option to set the charging current by a limiting  resistor  in hardware or by setting a voltage in some pin of the bq25703 ( by hardware manner)  ?? not by software by I2C !!

    in which registers  I set the battery voltages and charging current via I2C ??

    what I meant by battery chemistry is how to select that my battery is lead acid or lithium ion ??cause the bq25703 is multi chemistry charger??

  • 0 in reply to AIED BEBAR
    TI__Guru*** 146745 points

    Hi Aied,

    BQ25703 is an I2C controlled, buck boost charger.  TI does not have a standalone buck-boost or boost charger capable of lead acid charging.  The best standalone solution is a dc/dc converter to provide a high enough voltage for either the BQ24450 or the BQ24650.

    Regards,

    Jeff