🔋 Battery Size Chart
Dimensions (diameter × height), voltage, and IEC designations for every common battery format. Coin cell names encode their size: CR2032 means 20 mm across and 3.2 mm thick.
Voltage matters more than fit: a 14500 lithium cell is the same size as an AA but delivers 3.7 V instead of 1.5 V — enough to destroy devices not designed for it. Match both the size and the chemistry the device specifies.
Standard Household Batteries
| Size | IEC Name | Dimensions (∅ × H) | Voltage |
|---|---|---|---|
| AAA | LR03 | 10.5 × 44.5 mm | 1.5 V |
| AA | LR6 | 14.5 × 50.5 mm | 1.5 V |
| AAAA | LR8D425 | 8.3 × 42.5 mm | 1.5 V |
| C | LR14 | 26.2 × 50.0 mm | 1.5 V |
| D | LR20 | 34.2 × 61.5 mm | 1.5 V |
| 9V | 6LR61 | 26.5 × 17.5 × 48.5 mm | 9 V |
Alkaline cells deliver 1.5 V; rechargeable NiMH versions of the same sizes deliver 1.2 V, which most devices tolerate.
Button & Coin Cells
| Size | Dimensions (∅ × H) | Voltage |
|---|---|---|
| CR2032 | 20.0 × 3.2 mm | 3 V |
| CR2025 | 20.0 × 2.5 mm | 3 V |
| CR2016 | 20.0 × 1.6 mm | 3 V |
| CR1632 | 16.0 × 3.2 mm | 3 V |
| CR123A | 17.0 × 34.5 mm | 3 V |
| LR44 | 11.6 × 5.4 mm | 1.5 V |
| A23 | 10.3 × 28.5 mm | 12 V |
CR = 3 V lithium chemistry; LR = 1.5 V alkaline. Keep coin cells away from children — swallowing one is a medical emergency.
Cylindrical Lithium-Ion Cells
| Size | Dimensions (∅ × H) | Voltage |
|---|---|---|
| 18650 | 18.6 × 65.2 mm | 3.6–3.7 V |
| 21700 | 21.0 × 70.0 mm | 3.6–3.7 V |
| 14500 | 14.0 × 50.0 mm | 3.6–3.7 V |
Named for their dimensions: an 18650 is ~18 mm in diameter and 65 mm long. Capacities for quality 18650 cells run 2,500–3,500 mAh.