Energizer states 15 years, to 90% of rated charge.
Various threads on CandlePowerForums have discussed problems with older Battery Station cells, including catastrophic failures. I'm guessing they found a really from good price with a Chinese supplier (where most Lithium comes from) and learned the "If it seems too good to be true..." lesson.
PS. Some devices draw power even when off. Even flashlights can do this.