i think the exact battery quote was "The human generates more bio-electricity than 120-volt battery and over 25,000 BTVs of body heat. Combined with a form of fusion, the machines have found all the energy
they would ever need." that's not anymore outlandish than many many scifi concepts. here's one example -- warp speed. a vehicle travelling at hundreds of times the speed of light, which physics has told us is the speed limit of the universe. the assumption is that there are scientific methods we haven't acquired yet that would allow what now seems impossible. in the case of warp speed it is probably wormholes and the bending of spacetime. in the case of humans as batteries it is the "form of fusion" they mentioned. if they'd have said, we hooked one end of a jumper cable up to his nose and the other end to his balls and siphoned off energy, then i think you'd have a case. but introducing the intentionally-general "form of fusion" makes it directly analogous to the the warp speed example
for the record, i loved the first Matrix and hated the sequels. i think the reason i liked the original so much was because it was a "birth of a god" story. that's a rare movie concept. some were saying the Matrix stole from other genres, but i haven't seen many or any birth-of-a-god movies. and not only a birth of a god, but a character we are identifying with throughout. so it's kind of like we vicariously experience his ascension to a deity
that's why the sequels sucked so much. you have a god fighting people. why? it's never in question who's going to win. and where did his godly powers go? the end of the first Matrix wasn't "oh, i can stop bullets, scroe!" it was i am the one, i can see the code, i can stop time, i am a god. that all went away in the sequels. he's fighting people on diesels and werewolves and ghosts, when as a god, he should have been working to free the trapped lives still in the dreamworld. i mean, shit, isn't the ending basically that all the trapped lives stay trapped, the matrix stays intact, but whoopty freakin do, Zion's allowed to survive so they can keep throwing rave parties.
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what if nigger meant kite