Different Series of LiFePO4 Batteries: 12V, 24V, 48V & Custom Packs

Cylindrical lithium batteries are one of the most common types of rechargeable batteries. Among them, the 18650 and 26650 are two popular models. They are widely used in electronics, energy storage, and even electric vehicles. Let’s break down the differences between these two battery types.
What Is an 18650 Lithium Battery?
The name 18650 refers to its size: 18mm diameter and 65mm length, with the “0” indicating a cylindrical shape.
Battery types: Mostly lithium-ion or lithium iron phosphate (LiFePO₄).
Key features:
- High energy density in a compact size.
- Very stable and reliable performance.
Common uses:
- Laptops
- High-powered flashlights
- Power banks
- Wireless devices
- Heated clothing and accessories
- Portable instruments and medical equipment
What Is a 26650 Lithium Battery?
The 26650 battery is also cylindrical, but larger: 26mm diameter and 65mm length.
Key features:
- Bigger size means higher capacity compared to the 18650.
- Delivers more power output, making it great for heavy-duty applications.
Common uses:
- Power tools
- Solar lighting
- Energy storage systems
- Electric vehicles
- UPS backup power
- Communication and medical equipment
- Specialized flashlights
18650 vs 26650: Side-by-Side Comparison
Feature | 18650 Battery | 26650 Battery |
---|---|---|
Size | 18mm × 65mm | 26mm × 65mm |
Capacity | Typically 1200mAh – 3600mAh (most mature models fall between 1800mAh – 2600mAh) | Generally 3000mAh – 5000mAh |
Applications | Flashlights, laptop batteries, power banks, e-bikes, tool packs | Solar street lights, deep cycle battery storage, large power tools, backup systems |
Runtime | Common ratings: 2200mAh, 2600mAh, 3100mAh | Typically 4000mAh, 4200mAh, 4500mAh (longer runtime) |
Compatibility | Not directly interchangeable with 26650 due to size; adapters exist | Not directly interchangeable with 18650 due to size |
The 18650 is compact, reliable, and widely used in everyday electronics.
The 26650 offers larger capacity, stronger output, and better endurance, making it ideal for high-drain devices and deep cycle battery applications.
Both batteries have their strengths. The right choice depends on what you need—portability and compatibility, or higher capacity and long-lasting performance.