Compact USB Charger Efest Slim K1 1-Slot for Li-Ion Batteries up to 26650
- Brand: Efest
- Product Code: Efest Slim K1
- EAN: 6958946202207
- ISBN: 7167
- Availability: In Stock
8.60€
Efest Slim K1 – Compact USB 1-Slot Charger for Li-Ion Batteries up to 26650
Efest Slim K1 is a single-slot USB charger, ultra-compact, efficient and portable, ideal for daily use, travel, or emergency situations. It automatically detects the type of battery Li-Ion (IMR, INR, ICR) and applies the optimal current for a safe, fast, and balanced charge. Compatible with a wide range of cells from 10440 to 26650.
Technical Specifications
| Model | Efest Slim K1 |
|---|---|
| Type | Smart USB single-slot charger for rechargeable Li-Ion batteries |
| Input | DC 5V / 1A (via USB-A port) |
| Charge Current | 1A ±10% |
| Automatic Cut-off Voltage | 4.20V ±0.05V |
| Automatic Recharge Voltage | 4.10V ±0.10V |
| Standby Current | <20 mA |
| Activation Current | 50–100 mA |
| Operating Temperature | 0 °C – 40 °C |
| Compatibility | Li-Ion 3.6V / 3.7V batteries: 10440, 14500, 16340, 17335, 17500, 18350, 18500, 18650, 20700, 21700, 26500, 26650 |
| LED Indicator | Red – charging / Green – fully charged |
| Protections | Overcharge, overcurrent, short circuit, reverse polarity, automatic cut-off at charge completion |
| Body Material | High-strength flame-retardant ABS |
| Dimensions | 110 mm × 30 mm × 30 mm |
| Weight | ≈ 50 g (without battery) |
| Included Accessories | USB to Micro USB cable |
Key Features and Benefits
- Smart and safe charging: automatically monitors cell status and adjusts current.
- Universal compatibility: supports all cylindrical Li-Ion batteries from 10440 to 26650.
- Advanced protection: prevents overcharge, reverse polarity, and short circuits.
- Compact design: easy to carry, perfect for travel or daily use.
- Clear LED indicator: shows charging progress (red = charging, green = complete).
- Energy efficient: minimal consumption and high stability during charging.
Recommended Applications
- High-performance LED flashlights and professional lighting equipment.
- Vape mods using 18650, 20700, or 21700 cells.
- Portable electronic devices and rechargeable tools.
- DIY projects and portable power systems.
- Power banks, solar chargers, or USB charging stations.
Package Contents
- 1 × Efest Slim K1 Charger
- 1 × USB to Micro USB Cable
- 1 × Multilingual User Manual
- Original Efest packaging with authenticity seal
Image Gallery




⚠Important Note: This charger is designed exclusively for rechargeable Li-Ion batteries. Do not use with non-rechargeable batteries, Ni-MH, or Ni-Cd. Insert batteries respecting polarity (+ / –).
🔋The Efest Slim K1 is the perfect choice for anyone seeking a reliable, portable, and safe charger. Ideal for high-performance Li-Ion batteries used in flashlights, vape mods, tools, and modern electronic devices.
Tags: charger, USB, Li-Ion, Efest, Slim K1, 1 slot, portable, 10440, 14500, 16340, 18650, 20700, 21700, 26650, 6958946202207
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