Need RTC Battery with 20 Years Operational Life

Hi All,

I am working on a emeter project where the RTC battery is required to support for 20 Years.
CR2032 with 225 mAh and RTC DC1307 with worst case current of 800nA can easily support more than 20 years.
But I am not sure about the operational life of the Battery.
Vaarta states Operational life as 10 years in one of the graph.

Can anyone guide me which area I should work to get a battery with 20 years operational life?

Thanks and regards.

Battery manufacturers guarantee a shelf life (not operating) of no more than 10 years for a non-rechargeable Lithium battery and recently for alkaline battery cells.
It might last longer if you keep it cool.

You might try contacting some of the major battery manufacturers and see what they say.

Maxim should have some battery management IC's. e.g. the ones used inside of their RTC's IC's and select between two batteries. Their website is a mess, so o had a hard time finding anything. have an alternate place to look if interested. Maybe you could cascade this into 4 batteries and 3 monitors. Some of the RTC's from Maxim are getting 20 years, but with 10 guaranteed. The hard part is replacing them. They were not socketed on some Tek equipment.