Wont you need to replace the batteries around Year 10 and then this becomes a wash?
Curious!
Even if they're at 50% capacity, they would still work, right? But if there are other considerations, especially safety ones, then that would definitely be a consideration. I'm not sure where to learn about this type of thing.
LiFePO4 generally degrades to 80% capacity after 10 years, that's it. Safety isn't an issue.