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Power usage

  1. Mar 25, 2007 #1

    the attached image is from the back of my laptop.

    i'm trying to figure out how much watts it consumes per hour.

    i know that power is current multiplied by volts. so its 90.09 watts = 4.62 amps * 19.5 volts. is this the watts per hour?


    Attached Files:

  2. jcsd
  3. Mar 25, 2007 #2


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    I'm not sure, but the 4.62 amps may be what it takes to run the laptop as well as charge a low battery. It may not take this much current all of the time. Once the battery is charged current consumption probably drops off.
  4. Mar 25, 2007 #3


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    "...is this the watts per hour?"

    This is the amount of power consumed. The energy from 90 watts for one hour is 90 watt-hours; for two hours is 180 watt-hours.
  5. Mar 25, 2007 #4
    And you have to take in account the efficiency of the power brick, usually in the range of 90%, so the total power will be around 100.1 W
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