Key Features
- 3700mAh Capacity: Provides long-lasting power in the 21700 lithium-ion format.
- Flat-Top Terminal: Designed for devices and battery packs that require flat-top cells.
- Consistent 3.7V Output: Reliable nominal voltage with a 4.2V maximum charge level.
- 2.5V Cut-Off Voltage: Helps support proper discharge limits in compatible devices.
- Rechargeable Lithium-Ion Cell: Built for repeated charging and long-term use.
Overview
The Efest IMR 21700 3700mAh rechargeable battery offers dependable performance and extended runtime in a modern 21700 lithium-ion size. Featuring a flat-top design and unprotected construction, this cell is intended for devices specifically engineered to operate with 21700 batteries. It delivers stable power output and is well-suited for users who need reliable energy in high-capacity applications.
Applications / Uses
- 21700-compatible flashlights
- Portable power tools and equipment
- DIY electronics and custom battery assemblies
- Bench testing and evaluation projects
- Replacement batteries for compatible lithium-ion devices
Specifications
| Manufacturer: | Efest |
| Model: | IMR21700V1 |
| Size: | 21700 |
| Positive Terminal: | Flat Top |
| Nominal Capacity: | 3700mAh |
| Nominal Voltage: | 3.7V |
| Maximum Voltage: | 4.2V |
| Continuous Discharge Rating (Max): | 10A |
| Cut-off Voltage: | 2.5V |
| Protected: | No |
| Rechargeable: | Yes |
| Approx. Dimensions: | 21.5mm x 70.4mm |
| Approx. Weight: | 73.12g |
⚠ Important Safety Warnings
Improper handling or misuse of this lithium-ion battery can result in FIRE, EXPLOSION, or THERMAL RUNAWAY, causing personal injury, property damage, or death. Users must read and follow all safety guidelines before purchase and use. Click here to review the full safety guidelines.
- Critical Warning: Never carry loose batteries in your pocket, purse, or bag. Loose batteries can come into contact with metal objects like keys or coins, causing a short circuit, which may result in severe burns, fire, or explosion. Always store or transport batteries in a protective case.
- Intended Use: This battery is designed for integration into protected battery packs with a Battery Management System (BMS) or Protection Circuit Board (PCB). It is not intended for standalone use or for e-cigarettes, vaporizers, or similar devices.
-
Thermal Runaway: A chain reaction where heat from a failing battery
causes further overheating, potentially leading to fire or explosion.
- Causes: Overcharging, short circuits, physical damage, or exposure to high temperatures.
- Prevention: Use a smart charger, avoid damage, and store batteries in a cool, dry place.
- Storage & Transport: Always store batteries in protective cases to prevent accidental contact with metal objects. Never store loose batteries in pockets, purses, bags, or near conductive materials.
- Inspection: Do not use if the PVC wrapper, terminal insulator, or casing is damaged, dented, leaking, or bulging. Continued use could result in failure, fire, or explosion.
- Charging: Use a smart charger specifically designed for lithium-ion batteries and ensure the charger's voltage matches the battery's specifications. Never overcharge, over-discharge, or leave unattended while charging.
-
Prohibited Activities:
- Do not expose the battery to extreme heat, fire, or liquids.
- Do not short circuit, puncture, crush, or modify the battery.
- Do not charge or discharge beyond the manufacturer’s voltage range.
- Do not dispose of in regular trash—always recycle at approved facilities.
- Emergency Response: If the battery overheats, emits smoke, or swells, move it to a non-flammable surface (e.g., sand or concrete) and stop use immediately. In case of fire, use a Class D fire extinguisher or sand. Do not use water.
Disclaimer
18650Battery.com is not responsible for any damages, injuries, or claims arising from improper use, handling, or failure to follow these safety guidelines. Lithium-ion batteries require strict adherence to all safety protocols. It is the reseller's responsibility to ensure all safety warnings and product guidelines are effectively communicated to customers. Users and resellers assume full responsibility for the safe handling, usage, and distribution of this product.