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Using 2 button batteries to charge another button battery

Discussion in 'General Electronics Chat' started by stuee, Apr 19, 2018.

  1. stuee

    stuee Member

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    Hi,
    I have a button battery for my watch that i cant get local anywhere and need my watch working for a meeting tomorrow.
    I remember knowing that if you have a full aa battery and half full one in parallel then it drains the full to half then them both together. (kind of :) )
    Is there a way i can make a mini circuit with another same voltage battery top of and bottom sandwiching the flat battery and hopefully the other 2 will put some charge in the flat one.??????
    Ive ordered a battery today when i found nowhere in this small town has them.

    Please dont comment with negative posts, Im asking here for advice so i dont make a battery explode :)

    thanks
     
  2. audioguru

    audioguru Well-Known Member Most Helpful Member

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    There are many different chemical combinations in button batteries. Yours is probably non-rechargeable and if you try charging it from another battery then it might explode, burn or leak.
     
  3. dknguyen

    dknguyen Well-Known Member

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    The devil is in the details. Only for true rechargeables and even then very unsafe because it is uncontrolled. Coin cells are not rechargeable so it's even worse. Their chemistry does not allow it.

    It's not a matter of getting advice on how to do it carefully. It physically won't work.

    You are better off getting a new smaller battery of similar voltage and squeezing it into the watch.
     
    Last edited: Apr 19, 2018
  4. dave miyares

    Dave New Member

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  5. Pommie

    Pommie Well-Known Member Most Helpful Member

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    If you just need it for tomorrow then check other things in your house. Kitchen scales, vernier calipers, lights that clip on heels of trainers, hearing aids etc.

    What is the number of the battery?

    Mike.
     
  6. Nigel Goodwin

    Nigel Goodwin Super Moderator Most Helpful Member

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    Depends on the coin cell, there are many rechargeable ones available.
     
  7. dknguyen

    dknguyen Well-Known Member

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    Really? I've never heard of any. Every one I've seen is some kind of silver chemistry where shelf-life and self-discharge where the priorities at the expense of everything else.
     
  8. dave miyares

    Dave New Member

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  9. audioguru

    audioguru Well-Known Member Most Helpful Member

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    Tiny button batteries for hearing aids are available as rechargeable today.
     
  10. Nigel Goodwin

    Nigel Goodwin Super Moderator Most Helpful Member

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    A lot of the I2C clock modules come with a choice of either rechargeable or non-rechargeable batteries fitted, with the charging resistor missing from the non-rechargeable versions.

    LIR2032 is one that's in a module I just checked, a DS1302 module. I also just checked a DS3231 module (better than the DS1302), that has a non-rechargeable CR2032 fitted.
     

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