The small & fat Button Cells are nominally 1.5V
Usually bought as an assortment on a common cardboard
LR44 is a fatter 5.37 mm version of an LR43 x.xx mm My
measuring callipers use LR44 The slimmer larger diameter
cells, eg CR1620 for mens watches & PC main boards are
Lithium, 3.0 Volts.
Probably chemically more dangerous to humans, & cost a
usually bought individually.
Tip on battery numbering eg :
- CR1225 : 3V Lithium, 12 is 12 mm diameter, & the 25
is 2.5 mm height.
- 1654 is 16mm diameter and 5.4mm thick.
- 14500 is 14mm diameter and 50mm long.
- 18650 is 18mm diameter and 65mm long.