You have to remember that CR2016's are horrible under any sort of load. Typical fauxton usage is only a couple seconds, giving the batteries plenty of time to recoup. Being used for only brief periods of time, they seem to last for at least a year. If you find yourself needing a keychain light for much longer periods of time (ie. it's the only light you EDC), it's probably time to look into a good AAA keychain light like the LOD, Arc, E0, etc.