Couple of maths questions :)

Discussion in 'General Electronics Chat' started by zorbzz, Jan 3, 2011.

  1. zorbzz

    Thread Starter Member

    Jun 16, 2008
    20
    0
    Hi everyone, I was wondering if someone could work this out .
    I have a video camera that uses 9.3 volts and 6.4 watts.
    My battery is 1250mAh

    Any formula to work out how long the battery will last for at 6.4 watts?

    Also is 1250 mAh the same as 1.25 Ah?

    Thanks alot.
     
  2. #12

    Expert

    Nov 30, 2010
    16,337
    6,821
    Watts Law. Power = current times voltage. P=IE
    6.4/9.3=amps
    1.25 amp hours divided by amps = hours

    1250 milliamp hours is the same as 1.25 amp hours.
     
  3. jerry0

    New Member

    Aug 15, 2008
    2
    0
    I=P/E
    I=6.4 / 9.3 = .688A
    1.25Ah / .688A = 1.8hour
     
  4. zorbzz

    Thread Starter Member

    Jun 16, 2008
    20
    0
    Great thanks alot.
     
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