This sounds like a premise for a sci-fi movie... Time travelers who had far superior batteries, going back to the past, only to accidently reveal the formula/technique to a person from the past. And then to "fix the timeline", they decide that rather than "simply" giving it out, they'd go overboard by actually making this battery. And intentionally make it run for so long, that by the time it runs out and people cut it open, they would have already figured out the long batteries and time travel by other means, thus letting history proceed as normal.,(reply>), boenrobotkkkm,(reply>), You need to write movies for a living. You're genuinely through-and-through awesome =3,(reply>), I don’t think it’s enough for a movie plot, but it’ll do as an episode of Dr. Who.,(reply>), mind blown,(reply>), @WrenAkula That's what I'm saying!