Dead battery

[rxsuperhero]

I'm a newbie.  I put a new battery in my 57 drove it around for less than 20 minutes, turned the car off and then needed a jump. 

Why?

Background info. 
This happened on the first drive after I dug the car out from the grave. 
I put in a pertronix ignition switch.

[BWhitmore]

I would suspect that your new battery was not properly charged by the supplier of the battery.  A new battery should operate the car (with no accessories like a/c, etc.) for at least two hours.  I would drive the car back to the battery supplier and ask them to check the battery and the charging system. (simple test - should take less than 1 minute).

[rxsuperhero]

Let me define "new". Something I should of mentioned. I bought the battery late last year and have since had to recharge it. How does this effect things?

[BWhitmore]

It all depends on how the battery was stored.  If the battery was  stored in a very cold area that could cause the battery to have problems.  I would suggest that you charge the battery and then perform a specific gravity test.  You should be able to buy a tester at a good auto parts store for under $5-10. 

I would also suggest that you test the charging system of your car with a voltmeter.  I am no expert with batteries, but these are some good suggestions. 

[rxsuperhero]

Does this problem have anything to do with the generator?  Or is that impossible to tell from the forum?

[Frankenstein57]

Recharge your battery,  fire it up,then while its running carefully remove the positive cable, if it dies its not charging.