Battery drawing less current

Discussion in 'General Electronics Chat' started by tonir, Aug 23, 2012.

  1. tonir

    Thread Starter New Member

    Aug 9, 2012
    14
    0
    Hi,

    My battery is drawing less than 100mA current from my LM317 voltage regulator. The output current of voltage regulator is around 400mA. So i charge the battery daily for 5-6 hrs. So it takes 2-3 days to fully charge.

    Is it the problem with the battery or charging circuit?
     
  2. absf

    Senior Member

    Dec 29, 2010
    1,492
    372
    Are you talking about your 12V 7AH SLA battery as on your other threads ?

    7AH=7000mA/Hr

    As you are charging at the rate of 100mA, it would take 7000mA/100mA=70 hours to fully charge the battery when it is empty. Since you spent 3 days 5-6 hous/day that would give 18 hours. I would say that is quite normal if the battery is not really very hungry.

    Allen
     
  3. tonir

    Thread Starter New Member

    Aug 9, 2012
    14
    0
    hi allen,

    thanks for your reply. Though i have set the output current limit of my voltage regulator to 400mA the battery draws b/w 80mA-100mA whether it is full or empty.

    When the battery is empty, should it not draw more current? and as it nears full charge the current drawn should reduce isn't it?
     
  4. absf

    Senior Member

    Dec 29, 2010
    1,492
    372
    I am sorry I didnt follow your previous threads closely, so I dont know how is your final charger looked like.

    What I can think of are :

    1. Does your charger has the voltage capable to push 400mA into the battery?
    2. Is your transformer powerful enough to deliver enough current through the regulator.
    3. Is your battery in good condition (not expired)?

    May be you should provide the old links to your other threads which dealt with the same topic. So people here can refer to them easily without asking you for more details.....:rolleyes::confused:

    Allen
     
    Last edited: Aug 23, 2012
  5. Ron H

    AAC Fanatic!

    Apr 14, 2005
    7,050
    657
    Post the schematic of your charger.
     
  6. CVMichael

    Senior Member

    Aug 3, 2007
    416
    17
    I had the same problem. I bought a new battery, everything was fine...
     
  7. tonir

    Thread Starter New Member

    Aug 9, 2012
    14
    0
    Thanks CVMichael,

    I Guess have to buy new one too.
     
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