The Ansmann Powerline 4 Pro can simultaneously charge 1-4 AA or AAA rechargeable batteries each with their own adjustable charging current. It is a desktop charger designed for charging AAA & AA Ni MH or Ni Cd rechargeable batteries. 400m A / 600m A / 800m A for 1-4 batteries 400m A / 600m A / 800m A / 1500m A / 1800m A for 1-2 batteries The Ansmann Powerline 4 Pro charger has an LCD Display that shows the selected charging program for each slot. The charging programs are Charge, Discharge (discharging, charging), Refresh (Cycle of charging & discharging to refresh old batteries), & Test (Fully charges battery, discharges battery & measures capacity, recharges battery). The display also shows the individual monitoring of the cells as Voltage (V), Capacity (m Ah/ Ah), Time (hh:mm) & Current (m A). This charger offers microprocessor controlled charging & supervision of each cell, multiple over-charging protection per battery, auto cut-off function, trickle charging, reverse polarity protection, alkaline & faulty cell detection. In addition, the Powerline 4 Pro has a 5V 1000m A USB (Universal Serial Bus) socket for charging a variety of devices such as smart phones, for example iPhone, Samsung, Sony, Nokia & iPad. It comes with a 100-240V AC power supply with UK & EU interchangeable plugs & a 12V DC adaptor for use on the road. Ansmann offer a 3 year warranty with this product.