Battery Over Charge Protection Circuit

Discussion in 'Power Electronics' started by Ijaz Ul Haq Pukhtoon, Dec 14, 2016.

  1. Ijaz Ul Haq Pukhtoon

    Thread Starter New Member

    Dec 14, 2016
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    Hi,

    I want to build a overcharge protection circuit for my 12v battery charger.
    When the threshold voltage is reached, charging should be stopped.
    Any help appreciated.
    Please tell me as simple as possible
     
  2. Dodgydave

    AAC Fanatic!

    Jun 22, 2012
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    Use a comparator circuit with a 555 chip, or op amp....
     
    Robert Murphy likes this.
  3. R!f@@

    AAC Fanatic!

    Apr 2, 2009
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    Or a LM339 comparator....
     
  4. wayneh

    Expert

    Sep 9, 2010
    16,102
    6,217
    Better yet, get a battery manager IC appropriate for your battery chemistry. Something like this, maybe. (There are many others.)
     
  5. hp1729

    Well-Known Member

    Nov 23, 2015
    2,304
    284
    Design 708 overvoltage detector.PNG View attachment 116869
    What are you using now? Can you modify that?
    A voltage comparator monitoring the output of the battery, set for 13.8 V (Lead Acid type battery?). The output clears a latch that turns off power to the charger. Or maybe just cuts it down to a trickle charge.
    How is your electronics? Can you build something if given a schematic?

    Just a starting point ...
    (image updated for design error)
    Still not actually built yet, just a starting proposal.
     
    Last edited: Dec 14, 2016
  6. wayneh

    Expert

    Sep 9, 2010
    16,102
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    Actually one of the simplest and most widely used solutions is a LM317 circuit, adjusted to the targeted trickle voltage. Charging never really completely ceases, but it gets very small as the target is reached.
     
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