I usually defended the computer against power failures via a floor battery unit that is tied to it via USB so that when the storms come, kill the power to the home the machine has less than a hour of power. Makes for a orderly shutdown. I also have used to to protect other devices through a power strip onto it as well. (We had a generator as well but not part of this topic) power outages in tornado or ice season are frequent.
I found that rechargeable batteries with hearing aids or rather disposible cheap 20 dollar sound boosters sold at walmart to vary in reliability. Some lasted a year others lasted 3 years. However they were intended to be rather basic and disposed of when no longer working. Its only a temporary workaround in between hearing aids for me.
I recall going through a certain number of zinc air batterys size 13 for my hearing aids in trucking, it was 24/7 day and night always on and in winter would only last like 3 days before you put on new batteries. We kept them in a small heater area so that when it's -55 in places they will still be good. I believe I went through around 2 packs of 4 each week. That would be around 8.00 or so each pack, call it 100 dollars in batteries per month always keeping spares. I remember the old analog mercury batteries lasting 4 weeks per pair but today's computer hearing aids do not tolerate weak batteries below a certain voltage like the old pre computer hearing aids once did. (Analog) they don't make analog anymore in the USA.
I feel that hearing aids and cochlears can and will approach 20 years of use if taken care of. Mine lasted a average of 10 to 20 in trucking what with all the abuse and trauma in those days. Sometimes the lab was able to rebuild them once or twice in that lifetime of the hearing aids. technology is always getting evolving and improving so I would think that in the future the cochlear experience would be better. Possibly with new connections between the brain and ear system so you can hear better or maybe if we were daring, replace what Nature provided entirely. (Pipe dream...)
I realize my post is not fully cochlear related however technology continues to evolve and improve each human generation in my lifetime Ive seen hearing aids in various kinds get more reliable for longer periods before being replaced. There is no reason not to think Cochlears would be the same improvement over time. The surgeries and necessary details would be in the hands of the surgeon and I would imagine connections would get pretty interesting as time goes by with that.
Finally but not least, there are people I run into at the store now and then here who use Cochlear, I will ask them some of your questions the next time we run into one another sometime.
