Does Vader's suit have a life support system?

[YT300000]

So stormies could have a two hour supply of oxygen if those rebreaters are part of their kit.

No, all they would need is similar functioning and designed tanks as the rebreathers.

I would assume that such the miniturisations involved with such rebreathers are probably prohibitly expensive to equip Stormtroopers with similar capacity tanks, hence why they only have a twenty minute supply.

But its extremely possible Vader has one of those or similar hidden in his armour which would switch on as soon as he's not in a breathable atmosphere.

And its not a rebreather, its just a "breather" ie. oxygen tank.

[Spanky The Dolphin]

But its extremely possible Vader has one of those or similar hidden in his armour which would switch on as soon as he's not in a breathable atmosphere.

Yeah, that's a very good point.