Measurement of battery equipment
The voltage of a battery cell is determined by the chemistry used inside. For example, all Alkaline cells are 1.5V, all lead-acid''s are 2V, and lithiums are 3V. Batteries can be made of multiple cells, so for example, you''ll rarely see a 2V lead-acid battery. Usually they are connected together inside to make a 6V, 12V or 24V battery.