We see those ads for the Energizer Bunny that goes and goes, but we know the truth. That little bunny will run out of power at the least convenient moment.
I have often speculated that the people who truly make money from technology are the people who produce the batteries. Billions and billions of batteries. If you have owned a cell phone for several years, you know how performance fails as the life of the battery decreases. The same is true for recharging lithium-ion batteries.