You will have to define “3 years” as well. It can’t be a blanket 3 calendar year thing, it would have to be X number of cycles which the average user would realistically hit with 3 years of usage. Not someone glued to their phone playing games all day that need to charge three times a day.
Can you really guarantee that? I mean, it’s pretty much dependent on individual usage.
Sure you can. Car manufacturers do it today.
You will have to define “3 years” as well. It can’t be a blanket 3 calendar year thing, it would have to be X number of cycles which the average user would realistically hit with 3 years of usage. Not someone glued to their phone playing games all day that need to charge three times a day.