In this article, we will discuss the difference between AA & AAA battery. AA and AAA batteries are widely used in small electronic equipment. The main difference between AA and AAA batteries is the difference in size or dimensions and charge storage capacity.
The letter AA and AAAA do not stand any meaning, it is basically a way of expressing the dimension and nominal voltage. AA batteries are larger in size as compared to AAA. Why does the size of the battery matter? The simple reason is that every device has a specific dimension for the fitment of the battery in its battery slot. The dimensions of AA and AAA battery are shown in the below pic.

The battery slot in the device can accommodate a specific size of battery. AA battery can not fit in the AAA battery slot and, AAA battery can not fit in the AA battery slot. If we want to accommodate both types of batteries, AA and AAA, then we need to use adaptors.
Both AA and AAA batteries have the same magnitude of voltage, equal to the voltage that a bigger D battery has. A single-cell battery of AA and AAA size has 1.5 volts. If we need to increase the voltage, it can be done by connecting the cells in the series. For example, for getting 9 volts, we connect 6 numbers of AA or AAA cells in the series.
The charge storage capacity of the AAA battery is smaller than the AA battery. It means AAA battery has a smaller amount of electrochemical material compared to the electrochemical material of the AA type of battery. This means the AAA batteries are suitable for those devices that need low power for their operation. There are no rules for use of AA and AAA batteries. However, if we use AAA batteries for equipment that demands more power, then they will exhaust soon and we need to replace the battery more frequently.
The device manufacturer provides the battery slot according to the device’s power requirement. Therefore, if the device needs more power, it has an AA battery slot.
More than one cell is required to raise the voltage in devices such as toys and electric torches. For such applications AA battery is suitable. AAA batteries are suitable for the devices like clocks and remote controllers. These devices do not require much power. AA and AAA batteries are also called alkaline batteries. These batteries are made of steel and a mixture of zinc/manganese/potassium/graphite, paper, and plastic. It is possible to recycle these batteries because of non-toxic materials.
For rechargeable batteries, we need a charger that perfectly charges the batteries. For charging both AA and AAA batteries the charger should be compatible to charge both types of batteries.
Comparison of AA and AAA Batteries
- AAA batteries are smaller in size compared to AAA. The smallest battery is of pin-shaped, 3.5mm diameter lithium-ion.
- AAA batteries have a smaller amount of electrochemical material as compared to AA.
- AAA batteries hold a smaller amount of charge as compared to AA.
- AAA batteries are suitable for small and low-power devices, while AA batteries are suitable for high-power devices.