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Electro-Magnet with a Car Battery Help

  1. Nov 12, 2011 #1
    Hello everyone.

    I'm glad to be part of the Physics Community, I've read a lot of interesting threads, and I think now i'm ready to be party of it!

    For my project, I'm trying to create a ElectroMagnet using a Car Battery. The specifications for this battery are..

    • 12V
    • 390A
    • 65 RC - What does this mean?
    • 43 AH - What does this mean?

    As you can see, I have no idea what those two mean, so any info would be nice :)

    Looking on amazon.com for some wire for my electromagnet, I searched a post before saying I would need at least 404ft of wire. I don't want to short circuit the battery, so I think that might be enough?

    Also a question. I came across this on amazon: https://www.amazon.com/Fi-Shock-WC-...?s=home-garden&ie=UTF8&qid=1321110814&sr=1-3"

    Would it be possible to use Steel wire than copper wire? Or would copper wire be the only option? I'm thinking around £10-16 maximum i'm willing to spend.

    Any help would be appreciated.

    - Owen.
    Last edited by a moderator: Apr 26, 2017
  2. jcsd
  3. Nov 12, 2011 #2


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    12, volts
    390A, cranking amps
    RC65, is for reserve capacity
    AH43, Amp Hour capacity until fully discharged.

    This is a starting battery that's optimized to give very high "short" bursts of current.

    Don't use iron wire unless you want to create a space heater. The resistance is far too high. That fence wire for high voltage, low current applications.

  4. Nov 12, 2011 #3
    Ah ok then. Thanks for the info and site!

    If I wanted to create this magnet, when I say would it be safe of doing it directly, Wire to terminals? Or would I need to have at least 404ft of 14gauge copper wire to compensate for the voltage it is giving out?
  5. Nov 12, 2011 #4


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  6. Nov 12, 2011 #5
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