Beam & BatteryPortable Light, Battery & Charging Guides

Editorial guide

Flashlight battery sizes and cell codes

Find common cell codes and the dimensions published for specific examples.

In this guide

A cited lookup of common cell labels, batteries and published dimensions.

Use one shared scale

Every silhouette in the chart uses the same 0–80 mm (0–3.15 in) height axis and the same 2px/mm scale for diameter. Exact millimeter values and direct inch conversions appear together.

Read the label and exact dimensions together. The chart uses named manufacturer examples, so each shape represents that cited battery rather than every product sharing the same code.

Protected and USB-C versions can be larger

Protection circuitry and charging hardware can change the finished length and sometimes the diameter. The chart keeps bare, protected and USB-C-equipped examples visibly labeled instead of collapsing them into one nominal size.

The bare and protected 18650 and 21700 examples are especially useful because they show how two products in the same family can occupy different physical space.

Size is only the physical check

Two batteries with similar dimensions are not automatically interchangeable. Voltage, chemistry, protection, terminal style and the device design remain separate requirements.

Use this chart to understand physical size, then confirm the exact permitted battery in the flashlight or charger manual before buying a replacement.

Battery dimensions on one shared scalePublished dimensions from each linked record. Height and diameter use the same 2 px/mm scale; inch values are direct conversions. Cap and wrapper details are schematic.
  • Primary / non-rechargeable example
  • Rechargeable example
  • Protected label

Scroll horizontally to compare all 13 cited examples on the shared scale.

AAA / E92PrimaryØ 10.5 mm / 0.413 inH 44.5 mm / 1.752 inSource record
AA / E91PrimaryØ 14.5 mm / 0.571 inH 50.5 mm / 1.988 inSource record
CR123A / 123PrimaryØ 17 mm / 0.669 inH 34.5 mm / 1.358 inSource record
14500 / Fenix protectedRechargeableProtectedØ 14.6 mm / 0.575 inH 50.5 mm / 1.988 inSource record
14500 / Keeppower protectedRechargeableProtectedØ 14.3 mm / 0.563 inH 52 mm / 2.047 inSource record
16340 / Keeppower protectedRechargeableProtectedØ 16.7 mm / 0.657 inH 36 mm / 1.417 inSource record
18350 / Keeppower bareRechargeableBareØ 18.3 mm / 0.720 inH 35 mm / 1.378 inSource record
18350 / Fenix protectedRechargeableProtectedØ 18.75 mm / 0.738 inH 39.2 mm / 1.543 inSource record
18350 / USB-C protectedRechargeableProtectedØ 18.5 mm / 0.728 inH 42 mm / 1.654 inSource record
18650 / Molicel bareRechargeableBareØ 18.6 mm / 0.732 inH 65.2 mm / 2.567 inSource record
18650 / Keeppower protectedRechargeableProtectedØ 19.1 mm / 0.752 inH 69.2 mm / 2.724 inSource record
21700 / Molicel bareRechargeableBareØ 21.55 mm / 0.848 inH 70.15 mm / 2.762 inSource record
21700 / Keeppower protectedRechargeableProtectedØ 21.9 mm / 0.862 inH 75 mm / 2.953 inSource record

Dimensions do not establish compatibility. Match replacement cells to the model manual.

Common designations with cited examples
DesignationExamplePublished dimensions and sourceExact sources
AAAEnergizer E92 alkaline LR039.5–10.5 mm (0.374–0.413 in) diameter; 43.3–44.5 mm (1.705–1.752 in) height. E92 data sheetEnergizer E92 data sheet
AAEnergizer E91 alkaline LR613.5–14.5 mm (0.531–0.571 in) diameter; 49.5–50.5 mm (1.949–1.988 in) height. E91 data sheetEnergizer E91 data sheet
CR123AEnergizer 123 / IEC CR1734516–17 mm (0.630–0.669 in) diameter; 33.5–34.5 mm (1.319–1.358 in) height. 123 data sheetEnergizer 123 data sheet
14500Fenix ARB-L14-1050 protected14.6 × 50.5 mm (0.575 × 1.988 in). Fenix recordFenix ARB-L14-1050 protected 14500
14500Keeppower P1450C2 protected14.3 × 52 mm (0.563 × 2.047 in). Keeppower recordKeeppower P1450C2 protected 14500
16340Keeppower P1634C protected16.7 × 36 mm (0.657 × 1.417 in). Keeppower recordKeeppower P1634C protected 16340
18350Keeppower UH1835P unprotected18.3 × 35 mm (0.720 × 1.378 in). UH1835P recordKeeppower UH1835P unprotected 18350
18350Fenix ARB-L18-1100 protected18.75 × 39.2 mm (0.738 × 1.543 in). Fenix recordFenix ARB-L18-1100 protected 18350
18350Keeppower P18350TC USB-C protected18.5 × 42 mm (0.728 × 1.654 in). P18350TC recordKeeppower P18350TC USB-C protected 18350
18650Molicel M35A bareUp to 18.6 × 65.2 mm (0.732 × 2.567 in). M35A data sheetMolicel INR-18650-M35A data sheet
18650Keeppower 1S1P protectedUp to 19.1 × 69.2 mm (0.752 × 2.724 in). protected 18650 recordKeeppower protected 18650 example
21700Molicel P45B bareUp to 21.55 × 70.15 mm (0.848 × 2.762 in). P45B data sheetMolicel INR-21700-P45B data sheet
21700Keeppower protected NMC2170021.9 × 75 mm (0.862 × 2.953 in). protected 21700 recordKeeppower protected 21700 example

Source notes

Manufacturer and standards sources for the facts on this page.

  1. Energizer E91 data sheet
  2. Energizer E92 data sheet
  3. Energizer 123 data sheet
  4. Fenix ARB-L14-1050 protected 14500
  5. Keeppower P1450C2 protected 14500
  6. Keeppower P1634C protected 16340
  7. Keeppower UH1835P unprotected 18350
  8. Fenix ARB-L18-1100 protected 18350
  9. Keeppower P18350TC USB-C protected 18350
  10. Molicel INR-18650-M35A data sheet
  11. Keeppower protected 18650 example
  12. Molicel INR-21700-P45B data sheet
  13. Keeppower protected 21700 example

More useful guides for light, battery and charging questions.