Broadly, the types of batteries used can be classified into two major groups, namely,
• Off-the-shelf batteries
• Proprietary batteries

Off-the-shelf batteries used in digital cameras

Mid-range consumer cameras and few low-end cameras use off-the-shelf batteries. Very few DSLR cameras accept such off-the-shelf batteries.

• AA batteries - These are dry cell-type batteries, which are commonly used, in almost all electronic devices. General alkaline batteries of this type have an electrical output of 1.5 volts. Rechargeable batteries can be recharged and have an output approximately 1.25 volts. AA batteries are longer in size than AAA batteries because they provide power for a much more longer duration, although the electrical output is same in both the types. Nickel-cadmium (NiCad) AA batteries as well as Nickel metal hydride (NiMH) AA batteries are available. Their capacities are different. Both types are used in digital cameras; however, NiMH AA batteries are more used. AA batteries have also started to come in the Lithium-ion (Li-ion) format. Since, Li-ion batteries do not supply power in the 1.5 volts range, they are not considered as true AA batteries.

• CR2 batteries - These are lithium based and are for single use only. They are mostly used in camcorders.

• AAA batteries - These are generally used in small electronic devices. Applications are in MP-3 Players, digital cameras, and TV remote controls. AA battery lasts longer than these batteries. AAA alkaline batteries give an output of 1.5 volts, whereas NiMH AAA batteries give an output of 1.2 volts.

• NiMH batteries - The acronym stands for Nickel metal hydride battery. This is a type of rechargeable battery similar to nickel cadmium (NiCd) battery. Since cadmium is an environmental hazard, instead of it hydride is used which is more environmental friendly. A NiMH battery is two or three times more long lasting than an equivalent NiCd battery. Standard digtal cameras use NiMH batteries along with other consumer goods like digital cameras, flashlights, etc. However, NiMH batteries tend to discharge power when not used.

• NiCD batteries - The nickel-cadmium battery is a rechargeable battery that is extensively used in toys and other electronics. Large capacities NiCD batteries, also known as wet NiCD are used in electric cars and as start batteries in aeroplanes. Due to their lower series resistance, they are an ideal choice for camera flash units.

• Li-Ion batteries - Lithium-ion batteries provide much more power than NiMH batteries. It is a type of rechargeable battery and is very popular in consumer electronics. They need adequate care else their lifespan shortens. They have a very good energy-to-weight ratio and suffer no memory effect. They discharge very slowly, when not in use. After three to five years, they lose charge sufficiently and cannot be further recharged. Lithium polymer cell is the more advanced design of lithium-ion batteries.

Proprietary batteries used in digital cameras

These batteries are custom built as per the manufacturer's specifications. They are generally used as an aftermarket replacement parts or as an OEM part. Proprietary batteries are all lithium-ion. After a certain amount of recharges, usually until 500 cycles, they start degrading and have to be replaced. During their lifetime, they perform extremely well and when replaced the same proprietary brand battery is generally preferred. Both the two ends of the spectrum, low-end consumer models to high-end professional cameras, all tend to use proprietary lithium-ion batteries.