Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Homework Help: Current Electricity

  1. Jan 24, 2009 #1
    Hi there, I need some help in getting this calculation done. I need to find out the number of batteries needed to power 5 devices of 12V for 18 hours. The voltage of the battery is also 12. Power of battery is 9600 watts.

    Please help. Thanks!
  2. jcsd
  3. Jan 24, 2009 #2


    User Avatar
    Homework Helper

    Welcome to PF.

    The real question is what is the load?

    When you know the load - you know the amps.

    When you know the amps needed you know the amp-hours needed.

    When you know the amp-hours of the batteries ...
  4. Jan 24, 2009 #3
    sorry, I don really get your point, LowlyPion. Can you explain further in depth? thanks
  5. Jan 24, 2009 #4


    User Avatar
    Homework Helper

    It's not enough to know what the voltage is of the devices.

    You need to know how much power they consume.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook