The Efest LUC V4 charger is by far the best charger you can buy for your money! The Efest LUC V4 is a superior quality charger equipped with 4 charging channels and a large LCD Screen. This thing charges batteries rapid fast! The LUC V4 charger has 4 built in independent charging channels with reverse polarity protection, short circuit protection, overcharge protection and a zero voltage activation function. It can also automatically monitor battery voltage. The Efest LUC V4 charger is compatible with most 3.7V Li-ion or LiMn batteries such as: 10440, 14500, 14650, 17670, 18350, 18490. 18500, 18650, 18700, 26500, 26650 etc.