Iron Man's power source

Throughout the first 2 Iron Man movies, it was made clear that the suit cannot be powered by anything else than an arc reactor. As a matter of fact, this was a huge point in Iron Man 2 "“ Tony Stark dying, because he was unable to find a means of improving the arc reactor.

So it was pretty weird when, in the third Iron Man, Tony Stark decides that the arc reactor can function as a rechargeable battery. When his top of the line suit remains without power, he simply plugs it in and waits for it to recharge.

In order to better fit the storyline of Iron Man 3, another type of retconning is also used. Instead of having the suit powered by the central arc reactor, each individual piece of the suit is powered by its own battery. Which is at least weird. But, hey, at least this was the best Iron Man flick to date, right?