For Cochlear brand your kit should include backup coils, and replacement is overnight. If you turn on lights (child mode) the processor lights indicate streaming with blue. I love my cochlear implants even though the integration UI and reliability is not perfect yet.

Advanced Bionics used to provide backups, but appear to have scrapped that program in favor of an exchange.

And don't get me wrong, I'm grateful for the technology. For example, I can now hear hummingbirds and squirrels chirping. Speech in noise also makes it a lot easier to hear in noisy environments.