Question: are duracell procell batteries lithium?
Answer: The Duracell (the "Copper-Top" people) ProCell 3-volt Lithium Battery seems to be a hi-performance-type cell -- they are marked "Professional Lithium Battery" and "Not For Retail Sale". These batteries are Made in the U.S.A. -- and "best used before" 2021 -- That's a very impressive shelf-life !!