21700 Batteries | High-Performance Lithium-Ion Cells

A 21700 battery is a high-capacity, rechargeable lithium-ion cell designed for superior energy efficiency and performance. With a standard size of 21mm in diameter and 70mm in length, these batteries were developed as a next-generation improvement over 18650 cells, offering increased power output, extended runtime, and higher energy density. They are widely used in electric vehicles, industrial equipment, flashlights, and renewable energy storage.

Key Features & Technical Specifications

• Battery Chemistry:

  • Lithium Nickel Manganese Cobalt Oxide (NMC - LiNiMnCoO₂): A balanced combination of energy density, power, and safety.
  • Lithium Cobalt Oxide (LCO - LiCoO₂): High energy capacity with moderate discharge rates.
  • Lithium Manganese Oxide (LMO - LiMn₂O₄): Superior thermal stability and safer operation.
  • Lithium Iron Phosphate (LFP - LiFePO₄): Excellent cycle life and extreme durability.

• Voltage: Typically 3.6V or 3.7V nominal, with a full charge voltage of 4.2V and a cutoff around 2.5V - 3.0V.

• Capacity: Ranges from 3000mAh to 5000mAh, depending on the chemistry and application.

• Discharge Rate (CDR): High-drain cells available with 30A, 40A, or even higher CDR ratings for demanding power needs.

• Cycle Life: Designed to last 500 to 1500+ charge cycles, based on proper usage and maintenance.

Protected vs. Unprotected 21700 Batteries

• Protected 21700 Batteries: Feature an integrated protection circuit to prevent overcharging, over-discharging, and short circuits. These are slightly longer than standard 21700 cells.
• Unprotected 21700 Batteries: Designed for battery packs or high-performance applications where external battery management systems (BMS) handle protection.

Popular Uses for 21700 Batteries

21700 batteries are becoming the industry standard for devices requiring longer runtime and more power. Some common applications include:
✔ Electric Vehicles (EVs): Used by Tesla and other automakers to improve battery range and efficiency.
✔ High-Drain Flashlights & Electronics: Preferred for LED flashlights, power banks, and vaping devices.
✔ Cordless Power Tools: Essential for drills, saws, and industrial machinery.
✔ Solar & Energy Storage Systems: Ideal for backup power supplies (UPS) and off-grid solar storage.

Choosing the Right 21700 Battery

Before purchasing, always check compatibility requirements for your specific device. Consider:
📌 Flat Top vs. Button Top: Button tops have an extended positive terminal, while flat tops sit flush.
📌 High-Drain vs. Standard Cells: Devices like flashlights and power tools benefit from high-CDR cells.
📌 Protected vs. Unprotected: Protected batteries offer extra safety features for standalone use.

At IMR Batteries, we stock authentic, high-quality 21700 cells from leading brands, ensuring reliable performance, safety, and longevity. Shop now to find the best power solution for your needs.