I use the unit with two 4 sets Sanyo 2500mAh NiMH batteries and have the batteries by measured with a measuring instrument. The power output is absolutely uniform, which speaks for the battery, the charging capacity after removal from the charging station regularly at around 98% of the maximum rated capacity of the battery - and that speaks for the charger, from other devices I have been accustomed to that, here are the top 20% "cut" were. Charging for these batteries has never claimed more than about 3.5-4 hours, usually less (of course comes down to how they are empty but for four hours at fairly empty battery with 2500 mAh is in a charger with 700 mA charging current Mignon cells quite well). Someone asked later what it did with the refreshing function on itself. The Ansmann hotline answered my email promptly within six hours with the following information: "Refreshing function means: The complete new charging technology with the automatic refresh function analyzes the battery after contacting the device. The unit discharges not fundamentally part-charged battery pack if the analysis of the battery does not result in damage. When the battery has no abnormalities and in charge. Discharge behavior this is unmistakable proof that the battery is ok. In this case a full discharge would be absolutely superfluous. With damage to the batteries by memory effect, the battery is discharged at 500mA. The discharge of the battery is possibly during Refreshing phase, indicated by red -. Green flashing, carried out " Not only the device, but also the fast service earn five stars.