Re smoke detectors. https://www.amazon.com/Four-Ultralife-Long-Lithium-Battery/dp/B004JWRI64
Last a very very very long time in smoke detectors. Built for shelf life which essentially is the condition those batteries are in while AC is on. They last about 7 to 8 years in my experience. I would guess there is a tiny bit of discharge measuring battery voltage taking down the 10 year rating in practice.
Thanks for the info. I will check it out.