Oh my goodness I've just learned a thing about The Matrix that causes it to make a lot more sense: In the original script the humans were used as neural network compute clusters by the Machines and as a crucial component of The Matrix itself.
Which is why humans who were aware of the simulation could control aspects of The Matrix - their minds were part of its foundation.
Unfortunately the test audiences had trouble understanding this concept so the studio changed the human role to "batteries".
@polychrome that idea actually makes sense! The whole battery thing never did.
@gpowerf @polychrome Morpheus didn't know why they needed humans, but he couldn't admit it - so he made up the power source story.
@goedelchen @polychrome quite likely :)
@goedelchen @polychrome or maybe Morpheus knew the truth but he found it difficult to explain to laypeople so he came up with the battery idea as anyone could understand that.