Difference between AA and AAA batteries.

The most popular battery formats are those classified as AA and AAA. What are their features?

Facts about AA batteries

Batteries with a diameter of 13.5 to 14.5 mm and a length of 50.5 mm are considered to be AA-compliant. Unofficially, they are called "finger". AA batteries are considered one of the most common in the world. They have been produced since 1907.

AA batteries are in the shape of a cylinder, which is usually made of metal and covered with a sheath. The plus and minus terminals are located at the ends of the case. The diameter of the first is 5.5 mm, the height is about 1 mm. The second pin is flat and includes a contact pad with a diameter of 7 mm or more.

The voltage of AA batteries is about 1.5 V. It can be noted that batteries of the Ni-Cd type, as well as Ni-MH corresponding to their format, have a lower indicator (1.2 V), and Ni-Zn devices - larger (1.6 V).

Depending on the type of electrolyte used in batteries, their weight differs. So, among the lightest - salt batteries (about 14-18 g), slightly heavier - alkaline (about 22-24 g), but the batteries weigh more than them. For example, the mass of nickel-metal hydride cells is about 30 g

In addition, the type of electrolyte affects the capacity of the battery. So, the corresponding figure for alkaline devices is 2980 mAh, almost the same as for nickel-metal hydride batteries (their capacity is 3000 mAh). Salt batteries usually have a capacity of 1500 mAh.

Facts About AAA Batteries

The appropriate type of battery is generally referred to as a 44.6 mm battery with a diameter of 10.5 mm. They weigh about 12 g. AAA batteries are unofficially referred to as "little fingers".

The batteries of this type have a voltage of 1.5 V. The batteries corresponding to their format are 1.25 V. The resource of AAA salt batteries reaches about 540 mAh. Capacity of alkaline batteries - up to 1200 mAh, nickel-metal hydride batteries - up to 1250 mAh.


The main difference between AA and AAA batteries is the size. The first are significantly more. This predetermines their higher capacity (when comparing cells that use the same electrolyte). But the voltage of both types of batteries is, in principle, the same.

Having studied the difference between AA and AAA batteries, we will reflect the conclusions in the table.


AA batteries AAA batteries
What do they have in common?
The same voltage - about 1.5 V, the use of the same types of electrolytes in the design
What is the difference between them?
Have a diameter of 13.5-14.5 mm, length - 50.5 mmHave a diameter of 10.5 mm, length - 44.6 mm
Have a capacity up to 2980 mAh, batteries - up to 3000 mAhHave a capacity up to 1200 mAh, batteries - up to 1250 mAh