Iron Man (movie)
Stark wakes up in a cave to find a man named Ho Yinsen standing over him.  Yinsen tells Stark that he took out as much shrapnel as he could. He also installed wires connected to a car battery to stop the rest of the shrapnel from reaching his heart and killing him.  Raza, the leader of the terrorists, orders Stark and Yinsen to build a Jericho missile for him.  Stark builds an arc reactor that produces clean power.  He uses it to replace the car battery that he has been carrying around.