How big are Fenix 14500, 18650 and 21700 batteries?Updated 12 days ago
Fenix 14500 batteries measure 14.5 mm x 50 mm, 18650 batteries measure 18.6 mm x 69-70 mm, and 21700 batteries measure 21.5 mm x 76 mm. These are protected cells, so they are slightly larger than the nominal sizes, and you should only use the battery size your light lists.
| Battery | Fenix model | Size |
|---|---|---|
| 14500 | ARB-L14-1600U | 14.5 mm x 50 mm (.57" x 1.9") |
| 18650 | Standard ARB-L18 (e.g. ARB-L18-2600, ARB-L18-3500) | 18.6 mm x 69 mm (.7" x 2.7") |
| 18650 | USB "U" series (e.g. ARB-L18-2600U, ARB-L18-3500U) | 18.6 mm x 70 mm (.7" x 2.8") |
| 21700 | ARB-L21 series | 21.5 mm x 76 mm (.85" x 2.99") |