Efest LUC S2 is a high-tech smart LCD chargers. It's with a big blue LCD display screen which can show the charging status clearly when charging the 3.7V batteries. It's designed with two built-in independent charging channels, which means two 3.7V batteries can be charged at the same time with the LUC S2. Moreover, the LUC S2 charger performs in highest safety. It can protect batteries from reverse polarity, short circuit, over-charging & over-discharging. LUC S2 is a high quality device with advanced battery charging program, it will protect the batteries automatically during charging.