What is the Voltage of AA Battery?
Blog | Published by Alex on July 22, 2025
The AA Battery Voltage
AA batteries are one of the most commonly used power sources in household and industrial applications. Understanding their voltage characteristics is essential for proper device compatibility, performance, and safety.
AA batteries are classified as
LR6 or R6 type under the IEC standard. Their typical dimensions are as follows:
1.
Diameter: 14.5 mm
2.
Height: 50.5 mm
All AA batteries maintain a consistent physical size to ensure compatibility across various devices.
Nominal Voltage of AA Batteries
The nominal voltage of a AA battery varies depending on the battery chemistry:
1. Alkaline AA battery:
1.5V (Common)
2. Zinc-carbon AA battery:
1.5V
3. Nickel-metal hydride (NiMH) AA battery:
1.2V
4. Nickel-cadmium (NiCd) AA battery:
1.2V
5. Lithium AA battery (Li-FeS2):
1.5V or 3.6V (for Li-ion variants like 14500)
Fully Charged and Cut-off Voltages
Different chemistries also have different full-charge and end-of-discharge voltages:
| Battery Type |
Full Voltage |
Cut-off Voltage |
| Alkaline |
1.6V |
~0.9V |
| Li-ion (14500) |
4.2V |
~3.0V |
| NiMH |
1.4V |
~1.0V |
Note: Li-ion 14500 cells are the same size as AA but output much higher voltage (3.6–4.2V). They are not suitable for standard AA battery devices unless specifically supported.
Discharge Behavior
1. Alkaline batteries have a gradual voltage drop during discharge.
2. NiMH batteries maintain a more stable voltage near 1.2V until near depletion.
3. Lithium batteries (Li-FeS2) offer long life and high energy density, with relatively stable output.
Application Considerations
1. Devices designed for 1.5V AA batteries may not function properly with 1.2V rechargeables unless they have low voltage tolerance.
2. Always check the device specifications when using 14500 lithium AA-sized cells to prevent overvoltage damage.
Highlights
The voltage of an AA battery depends on its chemistry. While the standard nominal voltage is 1.5V, rechargeable versions like NiMH and high-capacity variants like Li-ion differ significantly. Understanding these differences ensures safe and efficient battery use across applications.
