The powerline 4 light is designed for charging aaa and aa nimh or nicd rechargeable batteries this desktop charger is able to simultaneously charge 1 4 aa or aaa rechargeable batteries with individual supervision of each cell the lcd display shows battery voltage and charging status as a percentage the charger offers multiple over charging protection per battery auto cut off function trickle charging reverse polarity protection and faulty cell detection in addition the powerline 4 light