Increase battery of usb charger

Discussion in 'The Projects Forum' started by yitmat, Aug 5, 2012.

  1. yitmat

    Thread Starter New Member

    Aug 5, 2012
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    I have a portable usb charger that has these specs:
    Li-ion 3.6V 1200 mAh
    Input: DC 5V 400 mAh
    Output: DC 5V 450 mAh

    Can i add an old battery that has 3.7V and 1150mAh to the charger and increase the battery life of it?
    Would it be safe to just hook up the the negs to negs and pos to pos?
    Also what would be a better way to increase battery of the charger without buying a new unit?
     
  2. MrChips

    Moderator

    Oct 2, 2009
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    Seems ok to me.
     
  3. yitmat

    Thread Starter New Member

    Aug 5, 2012
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    I also thought it would be okay to charge the batteries through the 5V input on the portable charger, however would the output of the charger being 5V have conflict with the combined power of 7.4V rather than the normal 3.6V? Overload?

    Also would it be okay if I increased it futhermore with a 3.7V 1000mAh Li-ion battery and a 3.7V 1150mAh Li-ion battery? Total of 14.8V and 4500mAh. I really want to get some serious juice out of my charger.
     
    Last edited: Aug 5, 2012
  4. yitmat

    Thread Starter New Member

    Aug 5, 2012
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    I have heard about resistors and regulators, but im not sure if i would need them in the situtation. If the extra load does need it, could someone point meout how i could acheve it?
     
  5. MrChips

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    Oct 2, 2009
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    Now you've gone off-track.
    Two 3.7V batteries in parallel is still 3.7V, not 7.4V.
     
  6. yitmat

    Thread Starter New Member

    Aug 5, 2012
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    Opps, i thought it made sense to add them together. :(

    So would 4 batteries together all with different mAh charge effiecently, or would it lead to over charging the lower mAh batteries?

    I read somewhere about bridging(i think that is what it was called) the pos/neg with a pos thats already connected to a neg. Would that be neccessary in this situtation?

    Sorry for all the questions. Much questions from a much confused mind. :p
     
  7. MrChips

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    Oct 2, 2009
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    3.6V 1200mAH and 3.7V 1150mAH are basically the same.
    Make sure the batteries are the same technology and same rating.
     
  8. yitmat

    Thread Starter New Member

    Aug 5, 2012
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    Is 1200mah + 1150mah +1150 mah + 1000mah a bad idea?
    Would it better without the 1000mah?
     
  9. MrChips

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    Oct 2, 2009
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  10. yitmat

    Thread Starter New Member

    Aug 5, 2012
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