Electro-Magnet with a Car Battery Help

[owen_a]

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/dp/B0046ECYOQ/?tag=pfamazon01-20

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.

 

[nsaspook]

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.

CA is cranking amps measured at 32 degrees F. This rating is also called marine cranking amps (MCA). Hot cranking amps (HCA) is seldom used any longer but is measured at 80 ° F.

Reserve Capacity (RC) is a very important rating. This is the number of minutes a fully charged battery at 80 ° F will discharge 25 amps until the battery drops below 10.5 volts.

An amp hour (AH) is a rating usually found on deep cycle batteries. If a battery is rated at 100 amp hours it should deliver 5 amps for 20 hours, 20 amps for 5 hours, etc.

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.

http://www.batterystuff.com/tutorial_battery.html

 

[owen_a]

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?

 

[nsaspook]

I have no idea what you're doing but that's a hunk of wire. 404ft of 14 gauge is about 1.02 ohms.
http://www.cirris.com/testing/resistance/wire.html
http://www.magnet4less.com/product_info.php?products_id=181

 

[owen_a]

Yes, it is a lot, but I was thinking of this:
http://www.amazon.com/dp/B003M67VUG/?tag=pfamazon01-20

When it says crafting, I'm guessing it won't be compatible with holding the amount of power I'm trying to push threw it.