What are primary and secondary batteries ? Give one example for each.

primary battery
The battery (electro chemical cell) that converts stored chemical energy into electrical energy and which cannot be recharged and reused when the cell reaction is completed is called a primary battery
Ex: dry cell, mercury cell
secondary battery
The battery (electro chemical cell) that converts electrical energy of an external source into chemical energy (charging) and when external source is removed off, then chemical energy converts electrical energy(discharge).

EX - Lead accumulator (acid storage battery), Edison battery (alkali storage cell), Ni-Cd cell etc.