I bought my Alphasmart Neo sixteen months ago. I’ve used it to write close to a quarter million words since then. Tonight, I took the Neo apart to blow the dust out of the keyboard, and I took the opportunity to replace the original three AA batteries that came in the box. Those batteries have been the Neo’s sole power source for the entire time..
According to the Neo’s battery meter, they still had 68% charge remaining.
There’s no other mobile electronic writing device that comes close to even ten percent of the Neo’s field endurance. Alphasmart estimates the battery life at seven hundred hours, but I think they’re being conservative about it. The only equally portable writer’s tool that uses less power is the notepad/pen combo.