Cell phone batteries are actually a terrible example here though, because they're not designed for longevity. Pretty sure most of the deterioration happens at t

Cell phone batteries are actually a terrible example here though, because they're not designed for longevity. Pretty sure most of the deterioration happens at the extremes, so if being designed for longevity they'd probably only have half the available capacity because it'd be capped at both the top and bottom of the range so they never went above 80-85% and never below 35-40%.