Complete Guide to Battery Sizes

Understanding battery sizes is essential for selecting the right power source for your electronic devices. This comprehensive guide covers all common battery types and their specifications.

Cylindrical Batteries (Household)

AAA (Triple-A): 10.5mm diameter × 44.5mm length. 1.5V alkaline or 1.2V rechargeable. Used in remote controls, small flashlights, and toys.

AA (Double-A): 14.5mm diameter × 50.5mm length. Most common household battery. 1.5V alkaline or 1.2V rechargeable NiMH.

C Cell: 26.2mm diameter × 50mm length. 1.5V. Used in medium-drain devices like portable radios and toys.

D Cell: 34.2mm diameter × 61.5mm length. 1.5V. Highest capacity household battery for high-drain devices.

9V (PP3): Rectangular, 48.5mm × 26.5mm × 17.5mm. Contains six 1.5V cells. Used in smoke detectors and guitar pedals.

Coin/Button Cell Batteries

Coin cells use a standard naming system: CR = Lithium 3V, SR = Silver Oxide 1.55V, LR = Alkaline 1.5V. Numbers indicate dimensions: first two = diameter in mm, last two = thickness in 0.1mm.

Common sizes: CR2032 (20×3.2mm), CR2025 (20×2.5mm), CR2016 (20×1.6mm), CR1632 (16×3.2mm), CR1220 (12×2.0mm).

Lithium-Ion Batteries

18650: 18mm × 65mm cylindrical. 3.7V nominal. Used in laptops, flashlights, and electric vehicles.

21700: 21mm × 70mm. Higher capacity than 18650. Increasingly common in EVs and power tools.

14500: Same size as AA but 3.7V lithium. Not interchangeable with AA alkaline.

Specialty Batteries

CR123A: 17mm × 34.5mm, 3V lithium. Used in cameras and tactical flashlights.

A23: 10.3mm × 28.5mm, 12V. Used in garage door remotes and small electronics.

Choosing the Right Battery

Consider voltage requirements, capacity needs, discharge rate, and operating temperature. Always match the battery type specified by the device manufacturer.