Provide basic information on batteries.

(N/A) What is a battery?: Any battery or cell used as a source of electrical energy is essentially a galvanic cell where the chemical energy of a redox reaction is converted into electrical energy.
$(b)$ Characteristics of a battery: It should be reasonably light,compact,and its voltage should not vary appreciably during its use.
$(c)$ Types of batteries: There are mainly two types of batteries: $(i)$ primary batteries and $(ii)$ secondary batteries.
$(d)$ Examples: Dry cell,lead storage cell,$Ni-Cd$ storage cell,hydrogen fuel cell,etc.,are well-known batteries.