Comment by rolfus

Not quite; they estimate that the battery will hold at least 24 hours of charge after 15 years. Charging it back up takes one hour, and in the context of cochlear implants these are very good numbers. I think most people would be okay with a (let's say) 20-year reimplant cadence given the benefits of this technology - but this obviously depends on which country you happen to live in. I'm lucky enough to live in a place where cochlear implants (and the surgery) is free to whoever needs it.