I bought my security token the day they were released for FF11 (april of 2009), and it has worked since then. I still use it today, so it has been 2.5 years on the same token without running out of battery. Nothing has ever gone wrong with it, aside from a week or so ago the protective plastic coating on the screen started to peel off (so i removed it), but that actually made the numbers clearer and easier for me to read xD