Efest k4 battery charger

Regular price $29.95

Tax included. Shipping calculated at checkout.

Efest Slim K4 USB-C Battery Charger can be used to charge electronic cigarette (e-cigarette) external batteries of any size via a Type-C USB charging port. You can charge up to four batteries for vapes in this charger and it keeps you safe with its built-in intelligent protection chip that includes smart functions such as:

  • auto-detect charging
  • monitors and charges each slot independently
  • low voltage smart activation recovery
  • 0V activation recovery.

It is compatible with Lithium IMR 3.6V/3.7V batteries: 10440, 14500, 16340, 17340, 18350, 18490, 18500, 18650, 26500, 26650, 20700, 21700.

The Efest Slim K4 charger will even tell you what it's doing with its LED indicator color light that will turn blue in standby mode/full charged and white when charging.

Please note: a 2A USB port is recommended.


  • A four-bay charger can charge up to four batteries simultaneously
  • Compatible with many battery sizes, including 18650, 20700, 21700 & 26650
  • Charging speed: 4 x 0.5A, 3 x 0.5A, 2 x 1A, 1 x 1A
  • Automatically stops charging
  • Reverse polarity protection
  • Input: Tyep-C USB DC 5V 2A
  • Output: DC 4.20V±0.05V 0.5A*4/0.5A*3/1A*2/1A*1


  • Efest Slim K4 USB-C Battery Charger
  • Type-C USB cable
  • Warranty card
  • User manual