Nuh uh....if you have a battery you have a crude DC welder.
Don't tell people that! *Disclaimer: not my fault if you don't disconnect it from the truck first.* There, phew. I wonder how much damage it would cause if you didn't.
Edit: Better yet
Instructions:
Connect leads to positive and negative terminals (it doesn't matter which one goes where).
Start truck
Block throttle open to 3k rpm and leave it there
Connect ground strap to work piece
Insert stick into stinger
Run Bead
(The truck might bog a little this is normal. If you hear popping sounds from what you are welding, you are welding to fast, slow the puddle travel speed).
If you hear an explosion, you have finished your weld.