EFEST SLIM K2 2-BAY CHARGER

Efest Slim K2 2-Bay Charger

The Efest Slim K2 features a lightweight body and two independent bays to charge the most common Li-ion batteries. Its LEDs clearly distinguish charging from the end of the cycle, with no menu or manual selection needed.

Powered via micro-USB, it can deliver up to 1 A per bay with a suitable 5 V/2 A source. Its format accommodates 18650, 20700, 21700, and 26650 cells, making it a simple solution for many mods with removable batteries.

Why choose this battery charger?

• Two independent bays with up to 1 A current
• Slim body that is easy to carry
• Automatic shut-off and essential protections

Technical specifications

• Brand: Efest
• Bays: 2
• Batteries: Li-ion 3.6/3.7 V
• Formats: 10440 to 26650, including 18650, 20700, and 21700
• Input: micro-USB 5 V/2 A
• Current: up to 1 A x2
• Automatic cut-off: 4.20 V ±0.05 V
• LEDs: white while charging, blue when idle or charge complete
• Protections: reverse polarity, short circuit, and overcharge

Which batteries to use?

Check the format, voltage, and chemistry of each cell before placing it in the charger. Diameter compatibility does not always guarantee that protected batteries, which are longer, can fit into the bay. Never force a cell and respect the polarity indicated on each bay.

For a dual-battery mod, keep a pair of the same brand, same capacity, and with the same number of cycles. Charge both cells together and replace the entire pair if one shows abnormal wear.

Tips for safe charging

Inspect the battery's insulating wrap before each charge. Do not use a cell with torn wrapping, a deformed shape, or one that has been dropped. Place the charger on a stable, dry, and clear surface, away from heat sources. Use a cable and adapter that match the stated input, then remove the batteries once the cycle is complete.

Maximum current is only relevant if the battery and power source support it. A gentler charge may be preferable for smaller capacities. Do not leave a charge unattended for long periods and always transport batteries outside the device in an insulating case.

Batteries and chargers compatible with your gear

Compare this model with other battery chargers, check out the selection of batteries and chargers for e-cigarettes, or browse all vape accessories. The product sheets specify the bays, currents, and verified formats so you can choose without guesswork.