Thread:71.183.135.148/@comment-2106279-20160517035812

You wrote "It is never explained why Tony continued to keep the Arc Reactor inside his chest after discovering it was poisonous. As shown by the initial car battery setup, an external power source is more than capable of keeping him alive. Only the electromagnet, which is not composed of palladium, had to be inside of him, so moving the reactor out of his body until an alternative to Palladium was found would have been a valid, if slightly awkward, solution to the metal poisoning problem."

^ Uh, the explanation is pretty simple. He needs it to survive. In Iron Man 1, Yinsen made a crude car battery set up, but Tony Stark can't live his whole life with a car battery, nor would he, as his personality shows, would want a car battery to be hooked up to him 24/7. Also, the car battery halted the progress of the shrapnel reaching his heart, while the reactor stops it from moving. Second, he tells both Yinsen in Iron Man 1 & Harley in Iron Man 3 that the reactor powers the electromagnet that keeps the shrapnel out of his heart. So while the magnet may not require palladium, the reactor which powers the magnet requires palladium. And the biggest obvious answer to your question - he can't be Iron Man without the arc reactor. He can't wear/use the suit. In Iron Man 3, he charges the Mark 42 with a car battery. But in a deleted scene, we also see that he goes unconscious when the reactor is removed for more than a few seconds. If he lugging around a car battery and a wire came loose, he'd only have 5 seconds to notice it and put it back before he collapses. 