
Efest SLIM K1 Intelligent Charger
The Efest SLIM K1 Intelligent Charger is the ideal solution for those seeking a compact, efficient, and reliable way to charge their 3.6V/3.7V Lithium batteries. Designed with convenience in mind, this single-channel charger offers rapid charging, USB-powered connectivity, and advanced safety features. Whether you're at home or on the go, the SLIM K1 delivers reliable performance with a sleek design that’s easy to carry. Backed by a 3-year warranty, it’s perfect for daily use and ensures your devices stay powered up.
Key Features:
- Fast and Efficient Charging: Provides a 1A output for rapid charging, reducing downtime and keeping your devices ready for use.
- Clear LED Indicators: A built-in LED charging indicator keeps you informed of the charging progress at a glance.
- Smart Battery Activation: Revives undercharged batteries with its low voltage activation feature, extending their lifespan and improving performance.
- Enhanced Safety Features: Includes reverse polarity protection to prevent damage from improperly inserted batteries, ensuring safe and reliable charging.
- Wide Compatibility: Supports a variety of lithium battery sizes, including 10440, 18650, 20700, and 26650, making it versatile for all your devices.
Battery Compatibility:
- 3.6V/3.7V Lithium Batteries: Compatible with 10440, 14500, 16340, 17340, 18350, 18490, 18500, 18650, 20700, 21700, 26500, 26650.
Technical Specifications:
- Input: AC 100V-240V 50/60Hz or DC 5V 1A
- Output: 4.2V ± 0.05V or DC 5V 1A
- Battery Output Cutoff Voltage: 4.20V ± 0.05V
- Auto Recharge Voltage: 4.10V ± 0.10V
- Size/Type Compatibility: ✔ 18650, ✔ 20700, ✔ 21700
What’s in the Box:
- Efest SLIM K1 Battery Charger
- USB Cable with Type-C USB Port: 5V 1A
- User Manual and Warranty Card
- Scratch-off Validation Serial Number

Original: $4.99
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Efest SLIM K1 Intelligent Charger
The Efest SLIM K1 Intelligent Charger is the ideal solution for those seeking a compact, efficient, and reliable way to charge their 3.6V/3.7V Lithium batteries. Designed with convenience in mind, this single-channel charger offers rapid charging, USB-powered connectivity, and advanced safety features. Whether you're at home or on the go, the SLIM K1 delivers reliable performance with a sleek design that’s easy to carry. Backed by a 3-year warranty, it’s perfect for daily use and ensures your devices stay powered up.
Key Features:
- Fast and Efficient Charging: Provides a 1A output for rapid charging, reducing downtime and keeping your devices ready for use.
- Clear LED Indicators: A built-in LED charging indicator keeps you informed of the charging progress at a glance.
- Smart Battery Activation: Revives undercharged batteries with its low voltage activation feature, extending their lifespan and improving performance.
- Enhanced Safety Features: Includes reverse polarity protection to prevent damage from improperly inserted batteries, ensuring safe and reliable charging.
- Wide Compatibility: Supports a variety of lithium battery sizes, including 10440, 18650, 20700, and 26650, making it versatile for all your devices.
Battery Compatibility:
- 3.6V/3.7V Lithium Batteries: Compatible with 10440, 14500, 16340, 17340, 18350, 18490, 18500, 18650, 20700, 21700, 26500, 26650.
Technical Specifications:
- Input: AC 100V-240V 50/60Hz or DC 5V 1A
- Output: 4.2V ± 0.05V or DC 5V 1A
- Battery Output Cutoff Voltage: 4.20V ± 0.05V
- Auto Recharge Voltage: 4.10V ± 0.10V
- Size/Type Compatibility: ✔ 18650, ✔ 20700, ✔ 21700
What’s in the Box:
- Efest SLIM K1 Battery Charger
- USB Cable with Type-C USB Port: 5V 1A
- User Manual and Warranty Card
- Scratch-off Validation Serial Number

Product Information
Product Information
Shipping & Returns
Shipping & Returns
Description
The Efest SLIM K1 Intelligent Charger is the ideal solution for those seeking a compact, efficient, and reliable way to charge their 3.6V/3.7V Lithium batteries. Designed with convenience in mind, this single-channel charger offers rapid charging, USB-powered connectivity, and advanced safety features. Whether you're at home or on the go, the SLIM K1 delivers reliable performance with a sleek design that’s easy to carry. Backed by a 3-year warranty, it’s perfect for daily use and ensures your devices stay powered up.
Key Features:
- Fast and Efficient Charging: Provides a 1A output for rapid charging, reducing downtime and keeping your devices ready for use.
- Clear LED Indicators: A built-in LED charging indicator keeps you informed of the charging progress at a glance.
- Smart Battery Activation: Revives undercharged batteries with its low voltage activation feature, extending their lifespan and improving performance.
- Enhanced Safety Features: Includes reverse polarity protection to prevent damage from improperly inserted batteries, ensuring safe and reliable charging.
- Wide Compatibility: Supports a variety of lithium battery sizes, including 10440, 18650, 20700, and 26650, making it versatile for all your devices.
Battery Compatibility:
- 3.6V/3.7V Lithium Batteries: Compatible with 10440, 14500, 16340, 17340, 18350, 18490, 18500, 18650, 20700, 21700, 26500, 26650.
Technical Specifications:
- Input: AC 100V-240V 50/60Hz or DC 5V 1A
- Output: 4.2V ± 0.05V or DC 5V 1A
- Battery Output Cutoff Voltage: 4.20V ± 0.05V
- Auto Recharge Voltage: 4.10V ± 0.10V
- Size/Type Compatibility: ✔ 18650, ✔ 20700, ✔ 21700
What’s in the Box:
- Efest SLIM K1 Battery Charger
- USB Cable with Type-C USB Port: 5V 1A
- User Manual and Warranty Card
- Scratch-off Validation Serial Number












