The original 12C used three button cells known as LR44, SR44, A76, V76PX, S76, 357, AG13, V13GA, LR1154 and many others. These cells are approx. 11,6 mm (d) x 5,4 mm (h). They are available as alkaline, silver oxide and mercury oxide cells (now banned in most countries of the western world). There are also zink-air cells, but these don't make much sense here. All these button cells have a common nominal voltage of 1,35...1,55 Volts.
On the other hand, lithium button cells usually are LiMnO2 cells with a nominal voltage of 3 Volts or even slightly more. Therefore they are usually not available in the same size as other batteries with half that voltage. I never heard of a A76-sized 3 V lithium cell.
So it's alkaline and (preferably) silver oxide cells that are used in the 12C.
Dieter