There are a number of different types of batteries used by householders / businesses for a variety of purposes. The main types are:
Lead-acid: All so known as Wet Cell, they are rechargeable and have a large energy rating.
Lead-acid and Sealed Lead-acid batteries (SLA) are used to power vehicles, Alarms, fire exit signs and other industrial uses.
Zinc Carbon: Typical voltage 1.5 V, an old type and cheap, usually found in toys, torches, clocks etc.
Alkaline Manganese: Typical voltage 1.5 V, replacement for zinc-carbon said to be longer lasting than the zinc types. Usually found in radios, toys, torches, cameras,
Mercury, (button cells) are used in small applications e.g. cameras, hearing aids, pocket calculators, photographic equipment.
Lithium: (button cells) Voltage1.5 V to 3.6 V, high energy, can be found in watches, pocket calculators, cameras etc,
Zinc Air: (button cells) Typical voltage1.4V, usually found in hearing aids and pagers.
Silver Oxide: (button cells) Typical voltage 1.55V. Often sold as button cells, for use in calculators, cameras, watches etc
Nickel Cadmium (NiCad): Typical voltage 1.2 V. Can be charged over and over again. Often supplied as packs within appliances, used for toys, cordless power tools, emergency lighting, laptops etc.
Nickel Metal Hydride (NiMH): Typical voltage 1.2 V. These are a more environmentaly acceptable alterrnative to NiCad batteries. Uses are mobile phones,laptops and camcorders.
Lithium Ion (Li-Ion): Typical voltage 4 V. This battery is used in, laptop computers, mobile phones and cam corders. They have a higher energy output than NiCad and NiMH and are often supplied as packs within appliances. These batteries should not be allowed to short circuit between the end terminals.
Using rechargeable batteries reduces the number of batteries requiring disposal, but 80% of them contain nickel cadmium, a known human carcinogen, and therefore need to be disposed of safely.