Collection: 21700 Rechargeable Batteries

Our 21700 rechargeable batteries deliver next-level performance and runtime for today’s most advanced flashlights. At FlashlightWorld.com, we offer genuine 21700 Li-ion batteries from Fenix, Nitecore, Acebeam, and Klarus — engineered to provide consistent, safe, and powerful energy output.

These 21700 cells are designed for high-drain flashlights that demand more capacity and efficiency than traditional 18650 batteries. Each cell offers longer runtimes, improved heat management, and built-in protection circuits for peace of mind.

✔ 100% authentic Fenix, Nitecore, Acebeam & Klarus batteries

✔ High-capacity lithium-ion (up to 5000mAh)

✔ Built-in protection circuit (model-dependent)

✔ Ideal for high-lumen flashlights and professional use

✔ Shipped from Canada — fast, no customs, full warranty support

Power your flashlight with the latest 21700 technology from trusted brands. Reliable, long-lasting, and made for professionals.

FAQ

Q1. What is the difference between 21700 and 18650 batteries?

21700 batteries are slightly larger and offer more capacity and runtime — perfect for modern, high-power flashlights.

Q2. Which flashlights use 21700 batteries?

Most new-generation lights from Fenix, Nitecore, Acebeam, and Klarus use 21700 cells for maximum performance.

Q3. Are these batteries protected?

Yes, most models include a built-in protection circuit. Each product page indicates whether it’s protected or unprotected.

Q4. Can I use 21700 batteries in an 18650 flashlight?

No — only if your flashlight specifically supports 21700 cells. Check the manufacturer’s compatibility before use.