I was watching Star Wars a few days ago (episodes IV and V) and the droids (C-3PO & R2-D2) just keep going and going and going.
C-3PO at least shuts down sometimes, but I don’t think R2-D2 ever does.
I wish my phone had batteries like that.
And, hey, if electric cars had batteries like that, I bet gas fueled cars would go the way of the dodo. All gas stations would turn into battery stations.