Cylindrical Li-ion batteries are widely used in electronics, medical devices, power tools, and energy storage. Understanding their identification according to global standards ensures safety, compatibility, and efficient selection.
This guide explains cylindrical Li-ion battery markings based on IEC61960, including the meaning of letters, dimension codes, prismatic vs cylindrical cells, and practical examples.
1. Structure of Cylindrical Li-ion Battery Marking (IEC61960)
According to IEC61960, a lithium-ion battery model typically consists of:
- Three letters
- Five digits (for cylindrical cells)
- Six digits (for prismatic cells)
(1) First Letter — Negative Electrode Material
| Letter | Meaning |
|---|---|
| I | Lithium-ion rechargeable battery (built-in cell) |
| L | Lithium metal or lithium alloy electrode |
(2) Second Letter — Positive Electrode Material
| Letter | Meaning |
|---|---|
| C | Cobalt-based cathode (LCO) |
| N | Nickel-based cathode (NCM / NCA) |
| M | Manganese-based cathode (LMO) |
| V | Vanadium-based materials |
(3) Third Letter — Cell Shape
| Letter | Meaning |
|---|---|
| R | Cylindrical cell (main focus for this guide) |
| L | Prismatic or rectangular cell |
2. Dimension Marking for Cylindrical Li-ion Batteries
● Cylindrical Cells — 5-Digit Code
The five-digit code represents:
- First two digits: Diameter (mm)
- Last three digits: Height (0.1 mm unit)
Examples:
- 18650 → Diameter 18 mm × Height 65.0 mm
- 14500 → Diameter 14 mm × Height 50.0 mm
If diameter or height ≥100 mm, a slash is used: 20/1050
● Prismatic Cells — 6-Digit Code (for comparison)
Prismatic cell codes represent: Thickness × Width × Height.
- Any dimension ≥100 mm → use slash
- Any dimension <1 mm → prefix t (unit 0.1 mm)
Example: ICPt73448 → Thickness 0.7 mm × Width 34 mm × Height 48 mm
3. Common Cylindrical Li-ion Battery Models
● ICR18650
- I → Lithium-ion
- C → Cobalt-based cathode
- R → Cylindrical
- 18650 → 18 mm × 65 mm
This is the most widely used cylindrical Li-ion battery format.
● ICR20/1050
- Diameter ≈ 20 mm
- Height ≈ 105 mm (large cells use slash)
● Other Prismatic Example
- ICP083448 → Prismatic, 8 × 34 × 48 mm
- ICP08/34/150 → Prismatic, height 150 mm
Note: For this guide, we focus on cylindrical Li-ion batteries, but prismatic examples are included for reference.
4. Extended Codes for Battery Packs
Many manufacturers add additional letters for features and pack configurations.
(1) Battery Type
| Code | Meaning |
|---|---|
| D | Ni-Cd battery |
| H | Ni-MH battery |
(2) Capacity & Feature Codes
| Code | Meaning |
|---|---|
| A | Button top |
| B | Flat top |
| H | High temperature |
| P | High current / Power |
(3) Pack Count
- Example:
*3,*5
Sample Pack Labels:
- D AA 800 H * 5
- H SC 2200 P * 3
5. Simplified Three-Part Designations
● L C 18650
Cylindrical Li-ion battery, 18 × 65 mm.
● L P 083448 S H
Prismatic cell, 8 × 34 × 48 mm, steel case, high capacity.
● L P 083467 A R
Prismatic cell, 8 × 34 × 67 mm, aluminum case, rounded edge.
Conclusion
Understanding cylindrical Li-ion battery markings under IEC61960 allows engineers, procurement teams, and manufacturers to:
- Quickly identify cell chemistry
- Determine dimensions and shape
- Assess performance and special features
This ensures compatibility, safety, and efficiency across industries including medical devices, lighting, trail cameras, power tools, and energy storage.