This is a Super fast , which charges most batteries in under 2 hours. Easy to see the LED Lights bar shows charging progress . The battery charger can charge 1 to 4 AA/AAA Ni-MH/Ni-Cd batteries. It has 4 independent charging channels that allows you to choose any combination of sizes of batteries to charge simultaneously. Has reverse polarity protection that prevents inserting the batteries wrong way. Has jump start voltage feature i.e. the charger stores some charge so that even when the battery gets charged even when it has 0V. The charger has 4 LED indicators to indicate the charging status. The charger uses low charging current, hence your batteries will have a longer lifetime. Needs an input of 100-240 V.