High Drain 21700 40P 4AH Lithium ion Battery for Rdrones and UAVs, robotics systems, high-power flashlights
| Parameter | Specification |
|---|---|
| Typical Capacity | 4000mAh |
| Nominal Voltage | 3.7V |
| Standard Charge Voltage | 4.20V |
| Standard Charge Current | 2A |
| Max. Charge Current | 6A |
| Discharge Cut-off Voltage | 2.50V |
| Max. Continuous Discharge Current | 35A |
| Max. Pulse Discharge Current | 80A (2s pulse) |
| Initial Impedance | ≤15.0mΩ |
| Dimensions (Diameter x Height) | 21.40 ± 0.10 mm × 70.25 ± 0.15 mm |
| Weight | 68.0 ± 2.0g |
VTCBATT: 21700 40P 4AH Lithium ion Battery Manufacture in China
VTCBATT is a professional 21700 40P 4Ah lithium-ion battery manufacturer in China, specializing in high-rate battery solutions for demanding applications. With advanced production lines, strict quality control, and extensive experience in lithium battery technology, VTCBATT delivers reliable performance, high discharge capability, and long cycle life. We offer flexible OEM/ODM services, including customized battery packs, BMS integration, and tailored specifications to meet specific project requirements. Our batteries are widely used in power tools, electric vehicles, and industrial equipment, providing efficient and stable power solutions for global customers.
Full Certification & Extended Warranty
VTCBATT Lithium ion batteries meet global certifications including CB, CE, UL, and UN38.3, and offer a 14-month warranty—two months longer than standard—to maximize customer confidence and profit.
CertificationVTCBATT lithium ion batteries have passed numerous important international certifications, including UL1642, IEC62133, UN38.3, CE, ROHS, BIS and EU2024/1542, CE, ROHS, REACH, and KC certifications.
WarrantyVTCBATT Lithium ion batteries come with a 14-month warranty, 2 months longer than the standard 12-month warranty, providing extra coverage for shipping and customs clearance. This ensures customer confidence.
CustomizationDifferent sizes,capacities, connectors, discharge rates,and cases. Just inform us of your specific requirement, and our professional engineers can provide you with the customized Lithium ion battery proposal.
Flexible order quantity to support prototype testing and mass production.
Our technical and sales teams reply to your inquiry within 6 hours.
Test our lithium battery quality and performance before placing bulk orders.
Batteries certified to UL, CE, UN38.3, MSDS, ROHS, IEC62133, and more global standards.
High Capacity of 4000mAh
Experience extended runtimes. The generous 4000mAh capacity ensures prolonged battery life, reducing the frequency of recharges and keeping your devices ready when you need them.
10A Moderate Discharge Rate
Perfectly balanced power delivery. With a stable 10A continuous discharge rate, this battery is the ideal choice for powering low-to-moderate drain applications safely and efficiently.
Advanced Lithium-Ion Chemistry
Built with premium cell technology. Our lithium-ion chemistry offers high energy efficiency, excellent stability, and minimal power loss, ensuring a consistent power output.
Eco-Friendly, Rechargeable & Durable
Designed for the long haul. This highly durable cell supports multiple charge and discharge cycles without compromising performance, saving you money on replacements.
Upgraded 21700 Form Factor
Bigger size, better performance. The larger 21700 physical footprint naturally provides higher energy storage capacity and superior endurance than traditional 18650 standard batteries.
21700 Lithium ion Battery Advantage
This chart demonstrates the exceptional manufacturing consistency of VTCBATT cells. A remarkable 97% of the batch features a tightly clustered capacity between 4.060 Ah and 4.120 Ah, with the majority (69%) peaking at 4.080–4.100 Ah. This narrow distribution highlights strict quality control and highly reliable performance.
This chart highlights the exceptional batch uniformity of VTCBATT cells even under higher loads. An impressive 97% of the batch delivered capacities tightly clustered between 3.960 Ah and 4.020 Ah, with a dominant 69% peaking at 3.980–4.000 Ah. This precise distribution guarantees predictable performance and strict quality control.
These VTCBATT cells demonstrate excellent long-term stability and outstanding thermal management. Over nearly 350 continuous 4A charge-discharge cycles, they maintain a strong energy retention rate of 85% to 90%. Additionally, surface temperatures consistently remain between 30°C and 35°C, indicating minimal heat accumulation during prolonged standard operation.
Similar to the energy curve, the graph displays an initial sharp voltage drop (down to approximately 2.6V) due to the increased internal resistance characteristic of cold environments. This is followed by a distinct voltage recovery phase—peaking around 3.4V—which is caused by internal self-heating generated during the 20A continuous high-rate discharge. Following this peak, the voltage gradually declines until the cutoff. Under these demanding conditions, both battery samples successfully delivered a total discharge capacity of approximately 3.6 to 3.7 Ah.
These VTCBATT cells exhibit exceptional high-rate discharge capabilities. While the initial operating voltage systematically drops from 0.8A to a massive 50A continuous load due to standard internal resistance, capacity retention remains outstanding. The total delivered capacity experiences only a minor decrease, shifting from over 4.0 Ah to approximately 3.7 Ah.
The curves display an initial sharp voltage drop, which is typical for batteries operating in cold environments due to increased internal resistance. This is followed by a brief voltage recovery phase—likely caused by internal self-heating from the 20A high-rate discharge—before the voltage gradually declines. Under these conditions, both battery samples successfully delivered a total discharge energy of approximately 11.5 to 11.8 Wh.
Why Choose VTCBATT?
VTCBATT not only focuses on customised designs and excellent service to meet the diverse requirements of various customers, but also dedicates itself to precise and uniform manufacturing throughout all processes to ensure the highest quality batteries. Simultaneously, VTCBATT provides comprehensive support from pre-sales to after-sales, placing emphasis on customer feedback to build long-term, mutually beneficial cooperative relationships. VTCBATT’s professional sales team and technical engineering team stand ready to support you as your premier custom battery specialists, delivering reliable and prompt service at all times.
From the raw materials mixing to the cell test, VTCBATT adopts an automatic manufacturing process to maximize production efficiency and enhance the batteries quality, safety, and reliability. The entire manufacturing process is monitored and 100% tested before flowing to the next procedure to ensure zero defects before delivery.
Over the past 20 years, VTCBATT has built strong partnerships with customers in more than 50 countries worldwide. With reliable quality, responsive service, and tailored battery solutions, we have earned the trust of our clients—many of whom have maintained long-term cooperation and lasting friendships with us for over a decade. Together, we continue to grow and move forward toward a brighter future.
Application
The VTCBATT High Power 3.7v 21700 4000mAh lithium-ion battery is widely used in portable electronics and smart devices that require high energy density and stable power output. With a slim pouch design, it is ideal for Rescue-Hero Coast Guard Search & Rescue Heli, Teleoperated Robot, FPV Drone. This battery supports customized dimensions, voltage, and protection circuits to match specific application needs. Featuring low internal resistance, long cycle life, and reliable safety performance, the VTCBATT 4000mAh Lithium ion battery ensures efficient operation, extended runtime, and dependable performance for both consumer and industrial applications.
