Lead-Acid battery charger - leaking voltage? (solved)

Discussion in 'The Projects Forum' started by bushrat, Feb 28, 2015.

  1. bushrat

    Thread Starter Member

    Nov 29, 2014
    97
    23
    Hello Guys,

    Few days ago, I build a lead acid battery charger from schematics that I found online.
    battery circuit.jpg
    For now, it works fine, battery is charging. I added 2 LED's to help me see where power is in the circuit (to help troubleshoot in case of failure). The problem begins when I remove DC power supply, the LED's are still lit but slightly dimmer. What am I missing from the circuit?
     
  2. Dodgydave

    AAC Fanatic!

    Jun 22, 2012
    5,237
    790
    If the circuit is correct, then D1 is letting the battery discharge and may be faulty.
     
  3. MikeML

    AAC Fanatic!

    Oct 2, 2009
    5,451
    1,068
    You have a shorted D1?
     
  4. bushrat

    Thread Starter Member

    Nov 29, 2014
    97
    23
    Found it, thanks guys (and gals, if any). D1 is P6kE6.8 - breakdown voltage around 6.8 V, and that's what's getting back into the circuit.
     
  5. Dodgydave

    AAC Fanatic!

    Jun 22, 2012
    5,237
    790
    its a zener diode then ,
     
  6. MaxHeadRoom

    Expert

    Jul 18, 2013
    11,057
    2,608
    That is a TVS diode, no wonder!
    Max.
     
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