Vapcell K40 21700 4000mAh 30A/45A High-Drain lithium-ion Rechargeable Battery

High-Drain Performance. 4,000mAh Capacity. Built for Power-Hungry Devices.

The Vapcell K40 21700 4000mAh Rechargeable Battery is a high-performance, high-drain lithium-ion cell designed for applications that demand a strong combination of capacity, current delivery, and reliable performance.

With a 4,000mAh typical capacity and a 30A maximum continuous discharge rating, the K40 is an excellent choice for high-output flashlights, high-drain electronics, and other compatible devices requiring a powerful 21700 cell. Vapcell also specifies a maximum discharge current of 45A with an 80°C cutoff.

The K40 uses an INR chemistry, a flat-top configuration, and a nominal voltage of 3.60V, making it a popular choice for demanding applications where a standard protected battery may not provide the required current capability.

⚡ High-Drain 21700 Performance

The Vapcell K40 is engineered for devices that require substantial current.

With a rated 30A maximum continuous discharge current, this cell can deliver the high-current performance needed by many powerful modern flashlights and other compatible high-drain electronics.

Vapcell lists the K40's performance as being similar to the popular Samsung 40T cell.

Key Performance Features

• 4,000mAh typical capacity
• 3,900mAh minimum capacity
• 30A maximum continuous discharge
• 45A maximum discharge with 80°C cutoff
• 3.60V nominal voltage
• 4.20V full-charge voltage
• 2.5V end-of-discharge voltage
• INR lithium-ion chemistry
• 21700 flat-top design
• Approximately 68g

🔋 4,000mAh Capacity

High output doesn't have to mean sacrificing useful capacity.

With a typical capacity of 4,000mAh, the K40 provides a strong balance between runtime and high-current performance. Vapcell specifies a minimum capacity of 3,900mAh, measured at a 0.2C discharge rate.

That makes the K40 a great option for flashlight enthusiasts who want a battery capable of supporting high-output operation while maintaining useful overall runtime.

🔥 30A Continuous / 45A Maximum Discharge

The K40's standout feature is its high-current capability.

Maximum continuous discharge: 30A
Maximum discharge: 45A with an 80°C cutoff

The 45A figure should be understood as a maximum discharge specification under the stated temperature cutoff, not a continuous 45A rating. For normal use, the 30A continuous rating is the more important specification when determining compatibility.

Always verify that the battery's specifications match the requirements of your specific device.

🔦 Excellent Choice for High-Powered Flashlights

The K40 is particularly well suited to high-output 21700 flashlights that require a high-drain cell.

Its combination of capacity and current capability makes it an excellent battery for flashlight enthusiasts looking to get the most out of compatible high-performance lights.

Ideal for:

• High-output 21700 flashlights
• High-drain electronics
• Compatible portable power applications
• Flashlight enthusiasts
• EDC and outdoor gear
• Emergency preparedness
• Replacement 21700 batteries
• High-current applications

Important: Always confirm that your device specifically supports a flat-top, unprotected 21700 lithium-ion battery before use.

📏 21700 Flat-Top Design

The K40 uses the standard 21700 battery format and features a flat positive terminal.

Approximate dimensions:

• Diameter: 21.1mm
• Length: 70.6mm
• Weight: 68g

Because battery dimensions and device tolerances can vary, always check your equipment manufacturer's battery compatibility requirements before installation.

⚙️ Technical Specifications

Specifications are based on Vapcell's published K40 specifications.

🏆 Why Choose the Vapcell K40?

If you're looking for a high-drain 21700 battery with a strong balance of capacity and current output, the Vapcell K40 is an excellent choice.

With 4,000mAh capacity, 30A continuous discharge capability, 45A maximum discharge capability, and a flat-top 21700 design, the K40 is built for demanding applications where ordinary rechargeable batteries may not be enough.

For flashlight enthusiasts, the K40 offers the high-current capability needed to support many high-performance 21700 flashlights, while its 4,000mAh capacity provides useful runtime.

High Current. High Performance. Built for Demanding 21700 Applications.