There are mainly two types of batteries used in electric hair clippers:

Lithium-Ion Batteries: These are rechargeable batteries that are commonly used in electric hair clippers. Lithium-ion batteries are known for their high energy density and low self-discharge rates, which means they can hold their charge for longer periods of time. They also have a longer lifespan than other types of batteries and are lightweight, making them ideal for use in hair clippers.

Nickel-Metal Hydride (NiMH) Batteries: NiMH batteries are also rechargeable and are commonly used in electric hair clippers. They have a high energy density and are known for their long cycle life, which means they can be recharged and used many times before they need to be replaced. However, they are slightly less efficient than lithium-ion batteries and can be heavier, which can make the hair clipper feel bulkier to use.