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12V 19Ah Motorcycle Battery to Supercapacitor

  1. Jan 20, 2010 #1
    The Lead Acid Battery in my H-D '09 FXDF is rated 12V at 19Ah. If I understand the math correctly, I would need a 12V capacitor rated to 5,700F. Is this accurate?

    1 F = 1 As/V
    1 Ah = 3600 As
    19Ah x (3600As/1Ah) = 68,400As
    (68,400As/12V) x (1F/[1As/V]) = 5,700 F

    As I understand it, traditional capacitors are unable to deliver a consistent voltage as it's discharged or used. Is this also true of Supercapacitors? If my math is correct, this would seem like a futile endeavor considering the necessary capacitance and associated cost over traditional 12V 19Ah Lead Acid Battery.

  2. jcsd
  3. Jan 20, 2010 #2
    68,400As = 68,400 Coulombs. The battery should be able to deliver this charge with an output voltage change of about 1 volt. Thus the supercapacitor should be

    68,400 Coulombs/1 volt = 68,400 Farads.

    Bob S
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