This external battery charger is the latest innovation by Efest. This 4 bay charging unit gives you to select your charging current, choose between 0.5A, 1A & 2A (for 25500 and 26650 batteries) The unit has an LCD display that lets you see how each of your batteries are charging at the same time. As well as choosing the current, the unit also have 3 different charging modes CC (Constant Current) CV (Constant Voltage) or Trickle charge. The smart charger automatically detects what type of battery you are trying to charge (Li-ion, Ni-cd, Ni-Mh) and can automatically adjust the charging features accordingly. If you’re looking to retain optimum performance out of your batteries, this charger is a must have piece of kit.