The definition of when the light dies is when I (or my sensors) can’t see the light…
Can’t ship the cells internationally… postal regs and all that.
Dead cells may have some life left in them.
And all contest enterers should read that thread (All SOLD - 2AA Maglites "Flag Light" Nichia 219, Carlco TIR -) to the end… it already has over 100 hours on it…