Efest Luc V4 is a high quality 4-Bay charging solution brought to you by Efest. This charger features built in 4-Bay independent charging channels with reverse polarity protection, short circuit protection, over-current protection and zero voltage activation. This Charger will automatically monitor battery power and give an alarm notice. The Efest Luc V4 4-Bay Charger is compatible with most 3.7V Li-ion or LiMn batteries like 10440, 14500, 14650, 18500, 17670, 18350, 18650, 18700, 26500 and 26650. This device can charge 15270 or 14250 batteries while using spacer. With one fully charged battery in channel 2, the LUC V4 charger also has the capability of charging your favorite devices (phone/ipad/mp3) through its 2 USB ports.