Long term battery concern

[Carsen]

We all know that the HP Prime has a rechargeable battery in it and I have a concern about it. When the HP Prime's rechargeable battery dies, how can I replace it with a new one? Can I expect to be able to replace it's rechargeable battery 30 years from now?

My dad currently still uses his HP 15c everyday and is able to get batteries for it. It is turning 31 years old in 2018. Will I be able to do the same with the HP Prime?

If not, then I guess it's fine. After all, I'll have a HP 50g and a HP 48gx to be able to get batteries for. At least, it's more likely that AAA batteries will still be around 30+ years from now.