I had several that were just getting to about 100cycles that went south when I had to leave country for work and stored them at 1/2 charge. They had all puffed when I got back about 3 months later. The were doing good up to that point, very little loss in capacity.

I see companies advertising 300cycles so maybe thats a better idea of how long. Going to be a while before I get mine back to where I was.