The Efest Slim K1 Battery Charger is a compact and efficient single-bay USB charger designed for lithium-ion batteries.

It provides fast and stable charging at 1A while ensuring safety with multiple protection features.

Equipped with intelligent detection, it automatically adjusts charging functions and safeguards against overcharging, short circuits, and reverse polarity.

Ideal for users seeking a portable and reliable charging solution.

Main Features

• Single-bay compact USB charger

• Fast charging mode at 1A

• LED charging status indicator

• Reverse polarity, overcharge, and short-circuit protection

• Auto-detect and low voltage activation functions

• Smooth sliding spring tested for 15,000+ uses

• Chromium-plated steel cathode for precise voltage and low resistance

• Compatible with a wide range of lithium-ion battery sizes

Specifications

• Input: DC 5V / 1A

• Standby Current: <20mA

• Activation Current: 50mA – 100mA

• Charging Current: 1.0A ±10%

• Auto Recharge Voltage: 4.10V ±0.10V

• Cutoff Voltage: 4.20V ±0.05V

• CV Cutoff Current: <100mA

• Operating Temperature: 0°C – 40°C

• Compatible Batteries: 3.6V/3.7V Li-ion (10440–26650, including 18650, 20700, 21700, 26650)

• Package Includes:

  • 1x Efest Slim K1 Battery Charger

  • 1x USB Cable

  • 1x User Manual