18650
A rechargeable lithium-ion cell named for its size: 18 mm diameter, 65 mm long. The building block of laptop and e-bike packs.
- Voltage
- 3.6 V
- Chemistry
- Li-ion
- Size
- 18 × 65 mm
- Capacity
- 2000–3500 mAh
Specifications
| Type | Cylindrical |
|---|---|
| Chemistry | Li-ion |
| Nominal voltage | 3.6 V |
| Diameter | 18 mm |
| Height | 65 mm |
| Typical capacity | 2000–3500 mAh |
| Rechargeable | Yes |
| Also sold as | INR18650, ICR18650, NCR18650 |
Equivalent batteries
These codes describe the same physical cell as the 18650.
Can I replace 18650 with…
Cells that fit the same space but differ in chemistry or voltage.
Check before you swap. Batteries with similar dimensions are not always interchangeable with the 18650. Always verify voltage, chemistry and the requirements printed in your device manual before fitting a replacement.
18650 questions
What batteries are equivalent to the 18650?
The 18650 is sold as INR18650, NCR18650. All of these describe the same 18 × 65 mm li-ion cell at 3.6 V.
Can I use a 21700 instead of a 18650?
In many low-drain devices, yes — the sizes match. Check the voltage and chemistry against your device's requirement first, because a small voltage difference can matter in calibrated equipment.
How long does a 18650 last?
A 18650 holds a typical 2000–3500 mAh. Real runtime depends entirely on how much current your device draws and whether it is used continuously.
Is the 18650 rechargeable?
Yes, the 18650 is a rechargeable cell and must be charged in a charger designed for its chemistry.
Related batteries
Other cylindricals in the index.