Trickle charge - prevents the natural self-discharging process of rechargeable cells. Individual Charging Channels - enables you to charge different numbers and combinations of cells. USB-in/USB-out (switch control) - charge your batteries using the USB-port of your laptop as the power source or charge your devices directly from USB Charger. Minus Delta V - method which takes advantage of the fact that the cell voltage reduces slightly in the rechargeable battery (-Delta V), as soon as the cell is completely charged. Temperature control - the temperature of the rechargeable battery is measured whilst its charging. If it rises above a defined maximum temperature level, the charges switches itself off. Bad cell / alkaline / wrong polarity detection - contains criteria for switching off to prevent charging of primary cells, defect cells or cells with reverse polarity.