power consumption

Discussion in 'General Electronics Chat' started by pafrazier, Jul 19, 2013.

  1. pafrazier

    Thread Starter Active Member

    Jun 4, 2011
    57
    0
    Hi,

    When you connect a capacitor to a battery and the capacitor is charged to the batteries voltage. Is there any power consumed from the battery if it remains connected to the capacitor?

    Thanks
     
  2. shortbus

    AAC Fanatic!

    Sep 30, 2009
    4,007
    1,530
    A very small amount over a period of time, due to leakage of the capacitor. Why would you do such a thing as what you describe?
     
  3. Shagas

    Active Member

    May 13, 2013
    802
    74
    Also from what I read , the leakage amount depends on the type of capacitor with Electrolytics at highest and Film or ceramic (don't remember which one) with the lowest
     
  4. pafrazier

    Thread Starter Active Member

    Jun 4, 2011
    57
    0
    Hi Shortbus,

    I am just learning about electronics.

    Thanks
     
  5. wayneh

    Expert

    Sep 9, 2010
    12,103
    3,038
    An "ideal" capacitor has no leakage. A real capacitor has very little DC leakage, so little it could be hard to measure, and it's usually not considered a factor.
     
  6. ian field

    Distinguished Member

    Oct 27, 2012
    4,415
    783
    Aluminium foil caps are one of the highest leakage types.

    Ceramic & polymer foil caps have such low leakage you probably wouldn't notice any shortening of the battery's shelf life.

    In other words; the battery's own rate of self discharge is probably greater than almost any non-polarised capacitor.
     
  7. crutschow

    Expert

    Mar 14, 2008
    13,002
    3,232
    The leakage for a typical aluminum electrolytic is in the low microamp range, depending upon voltage and size, so even those shouldn't significantly affect battery life, expect perhaps for small button cell types.
     
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