Another idea: Apple could pop up a dialog at a certain point saying your battery is sub-optimal (but not doomed) and you should replace it for the best experience.
I’m sure that would go over GREAT.
I’m sure that would go over GREAT.
Most people don't understand that the degraded battery is the cause of the performance issues (its not very intuitive), so they should explicitely say that.
For laptops, as part of their hardware test they had a chart for the battery. The expected cycle count was listed in quite a few places (it was 200 for removable batteries and jumped to 1000 when they started making them non-removable). X was the cycle count and Y was the battery's maximum charge (I tried to find pics, but couldn't). The chart had a diagonal red line marked "defective." They replaced your battery if it was within the defective range, but not if your cycle count was too high.
Phones aren't any different, they're just more hand-wavy about the battery (they don't show or mention cycle-counts).