I have my copy of Shadows of the Empire (set between ESB and ROTJ) handy, luckily.
So yep, instruction manuals.
An old issue of Popular Telekinetics, perhaps?
I was thinking more along the lines of National Telepathic.
Nah. It was Yoda-ssey.
Wow, and to think that that magazine was once cool. They don’t even seem to have Ulysses the Robot any more.
Sorry to necropost, but excuse me?
I don’t remember Yoda dying anywhere in Empire, I’m pretty sure there was an extended scene in *Return where Luke returns to Dagobah to confront Yoda, and then Obi-Wan’s Ghost about their deception as to his relationship with Vader. 
While Shadows does a good job of explaining things, it really wasn’t necessary, as the perfectly logical assumption would have been that Yoda taught him, either during his first visit to Dagobah, or perhaps during a hypothetical return trip prior to Return.
Have but haven’t read SPLINTER, or the original STAR WARS novel, or a novel after RETURN OF THE JEDI, am not a fanboy, have never even thought of the Q until now.
But my gut response is they were Force-powered. Did you ever see a non-Jedi/Sith using one?
Yes, Han Solo uses Luke’s (who is unconscious) to cut open a tauntaun to keep him warm.
Well, uh, the LS had some residual Luke-Force power stored up in it. Yeah! That’s it!
Tiny, little Hamsters, running their iddy-biddy legs off on an exercise wheel.
Like the SDMB.
Er, the OP said the power source packs more punch than a AA cell…
General Grevious was establiashed as being not Jedi or Sith and having no significant Force sensitivity, yet was able to use multiple light sabers for extended periods of time. So I think it’s clear that their actual power source is technological, not Force-based.
I’ve heard this explanation before and although I believe it’s canon, it is nonsense (yeah, I know it’s fiction). The blade emits bright light; it can’t do that without expending charge.
Oh, I agree it’s nonsense. I’m just giving the canon explanation, not saying it makes sense in reality.
Han didn’t have some Force in him in order to shoot nearly blinded?
He must’ve had some force power to be able to casually dodge Greedo’s blaster shot impacting the wall right next to his head and not even flinch.
Has there ever been a lightsaber duel depicted where one combatant’s weapon ran out of juice?
Considering that the things can melt through multiple blast doors presumably made from some kind of über-alloy and put out enough power to pretty much instantly cut through anything else, I think it’s safe to say that the power loss to visible light emission is negligible. Visible light is relatively low energy, and by all indications you don’t need to wear radiation shielding around them and they don’t seem to put out any significant heat unless the “blade” is in contact with something, so it’s probably not radiating thermal energy or higher energy forms than maybe ultraviolet. We don’t see funky tans on the “human” Jedi, so it’s probably not even putting out UV.
Sure, the batteries would probably go flat eventually, but it’s putting out very little power so I would expect one to be able to run for practically forever if all it was doing was being on and not cutting anything. The power from one of these power packs might be in the gigawatt range for all we know. You could run a light source off something like that for an indefinite period of time, about, oh, a few million hours or so. In theory, you’re right, but for practical purposes a lightsaber would lose basically no power to light production based on the behavior we’re shown in the movies and other sources.
Once, but I’m not sure where Energizer Bunny commercials fit in the hierarchy of canon.
And physics nitpick, but “gigawatts” are a unit of power, not of energy. How much power a cell can supply tells you nothing about how long it’ll last. A unit of energy might be “gigajoules”, or “gigawatt hours” (that is to say, a 1 GWhr source could continue outputting 1 GW for an hour, or 1 watt for a billion hours, or 1000 watts for a million hours, before running dry).