In the Iron Man movie, Tony Stark mentions that he won't sell the Iron Man technology, because he only trusts himself to use it. Because he has an arc reactor built into his chest, his suit can interface with it for power. Unable to produce an arc reactor, Obadiah Stane steals the reactor from Stark's chest to power his Iron Monger suit.

In Iron Man 2, we see Tony's room of older Iron Man models, among them the Mark II and III armors. Both of these armored suits are shown with an arc reactor built into them. This enables James Rhodes to steal the Mark II suit during Tony's birthday party, equipping it as the War Machine suit.

Why would Tony store his extra Iron Man armored suits with power sources built in, when that would enable just anyone to walk in, put on a suit, and leave? He already had an arc reactor at all times. What would storing suits with built in power accomplish? Why would he make extra arc reactors anyway when he should've learned from Stane stealing his reactor tech? Is there a valid, in-universe reason for this, or is it just to enable Rhodey to easily steal a suit?

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    James Rhodes was a friend of Tony Stark. Maybe Tony installed standalone reactors to allow James (and other friends?) the opportunity to fly them when they come over to knock back some beers. Not to mention that they look cooler with the reactor in them.
    – Xantec
    Commented Apr 17, 2012 at 19:04
  • That would be an okay explanation if Tony wasn't Tony. After seeing his tech fall into the wrong hands in Iron Man 1, he gave up weapons production completely. If he was willing to completely change his livelihood because of his kidnapping experience, I doubt highly he'd let his buddies play with highly advanced weapons systems. Commented Apr 17, 2012 at 19:08
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    Actually it's even noted in the movie that he allowed James Rhodes to take one. Commented Apr 17, 2012 at 19:59
  • @KevinHowell I seem to remember he was pretty pissed. He even asked for it back after the final battle, but Rhodes refused. I think he just valued Rhodey's friendship more than he valued the suit, so he decided to let it slide. Commented Apr 17, 2012 at 21:16
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    Yes that's what he said to Rhodes but the Black Widow I think pointed out that he had voice recognition that activated the armor. Rhodes stepped into the armor and was instantly able to use it only because Tony had to have programmed him in as a user. Remember Tony also thought he was sure to die from the shrapnel in his heart at this point and drinking quite a bit. Commented Apr 17, 2012 at 21:32

13 Answers 13


Suits with built in power-supplies would ease the strain on the arc reactor system built into his body.

Since he was already having a problem with his internal arc reactor, it made sense to experiment with suit models that had their own arc reactor built-in to the suit. This would also aid in reducing the speed at which the power supply in his body burned out. It would make sense to build his suits with alternative/redundant power-supplies, just in case.

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    Also has the added benefit of not being left for dead if a villain wants to steal an arc reactor. Commented Apr 17, 2012 at 20:20
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    Ah. Makes sense. Have a cigar. Commented Apr 18, 2012 at 16:51

In his conversation with Fury and Romanoff they they practically force him to admit it was a setup and he made the suit available to Rhodey all along. In fact, I think he wanted him to take it in the first movie to back him up, but Rhodey just says "next time". Just like Fury, Stark has a lot more going on than what you see on the surface, you have to read between the lines.


He built them so that in the event of his death, Rhodey would be able to step in and become Iron Man. Note that in Iron Man 2, Rhodey knows how to fly the suit, the right poses needed to shoot the hand beams, and level off and fly, whereas Pepper did not in Iron Man 3. So I'd say it is safe to assume that between 1 and 2 that Stark taught Rhodey how to use the suits, in case of death by palladium poisoning. He is an optimist after all.


"Spoiler alert". In Iron Man 3, Tony asks Jarvis to activate the armors so they could fly to his rescue. It makes sense that they have a built-in power supply so they could fly on their own in emergency situations.

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    Of course this one is, at least, part of the correct answer. It should be noted also that in The Avengers, the suit flies on its own to match Tony's fall and get to his arms. This would have been impossible without an ARC reactor on it.
    – Envite
    Commented Apr 24, 2014 at 15:39

It is noted in Iron Man 2 that the arc reactor in his chest also powers the suit (when Jarvis says extended use of the suit was accelerating his condition) it is quite plausible that, because the reactor core gets depleted, the reactor in his suit served as a backup power source for both jobs or vice verse. If, for example his chest reactor's core was depleted and he had no access to a replacement, the suit would take over the job and save his life.

It was probably also a solution to the slow poisoning in that the suit wouldn't be dependent on his chest core. I think he would have known about the poisoning in Iron Man 1 but the issue was only fully addressed in IM2.

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    It's worth noting that the smooth goop stuff that he's drinking in Iron Man 2 to minimise the poisoning actually appears, without comment, in Iron Man 1 when he's building the armour in his home lab. Nice easter egg.
    – Jon B
    Commented Aug 22, 2014 at 3:39

He thought he was going to die from the blood toxins his internal Ark reactor was leaking. He was trying to leave the suits as his legacy.


His arc reactor powers the electromagnet that keeps him alive after he was almost killed by terrorists.

The arc reactor in the suits power the suit(s) and also powers a powerful repulsor to damage his opponents,

The reason he dosen't use the first one (the one to keep him alive) for the suits is because they have different jobs, and control/do different things...


Maybe because in the first Iron Man film, Obadiah stole the arc reactor from him and he was about to die, so for his safety he made more arc reactors so he could use it in an emergency (only my opinion).


He only uses the power from the arc reactor in his chest when his suits power runs out, like a back up, obviously he's not going to have a suit of armor to protect him that drains the power of the thing protecting his heart, or he'd just die in the suit, I believe he has other power sources in the suit, including another arc reactor.

  • Do you have any references you can site to back this up?
    – Monty129
    Commented May 5, 2013 at 11:07

Also if you watched closely, Nick Fury already cleared up the question of 'Why do it when anyone, as Rhodey, hijack the suit?'

JARVIS has them all locked and only allows access to Tony, except, ofcourse if there is a special parameter for Rhodey, or anyone else.

War Machine, the suit Rhodey takes, could be hacked by Vanko because HAMMER "updated" the software.

And Imagine you have a battery, in your chest, that keeps you alive, and you die when that battery runs out. Would you risk running your PC on that if you could easily build another one, INTO your computer? I wouldn't.


In the 1st installment itself, Obadiah is shown stealing the reactor by some means and feeding it into the Suit which he uses to create havoc.

I feel in case of Tony, he connects the suits and powers them from his chest, which saves the overhead of creating a new arc-reactor for each version of his suit. The reactor cavity in suits hot-wires to his chest. But if you don't have reactor in your chest, you feed it externally and connect it to power your suit. Thats the possible explanation @Gabe Willard

  • This sounds like mere speculation as you cite no sources. Commented Jun 22, 2018 at 14:34
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    This doesn't actually seem to answer the question. We know an external reactor can power a suit; the question is why would Tony store old suits with reactors attached, as that would allow someone other than him to use them, which he doesn't want to happen?
    – RDFozz
    Commented Jun 22, 2018 at 15:32

Maybe he did that to provide more energy to the suits so the suit does not lose battery and it give the suit extra power to the repulsors and the suit it self

  • Do you have a source for this idea?
    – Null
    Commented Jan 19, 2015 at 17:42

In Iron Man 2, when Nick Fury is talking to Tony, Widow mentions that the suits have a protection feature which does not allow unauthorised access. So it means not just anyone could walk in and wear a suit.

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