Built-in cooling fan and Built-in CPU, analyses battery condition via memory chip in the battery, and controls current, voltage and temperature of individual cells within the battery to produce optimum and fast charging.Charging times for:-BL 5Ah - 45 MinutesBL1840 4Ah - 36 MinutesBL1830 3Ah - 22 MinutesBL1430 3Ah - 22 MinutesBL1415 1.3Ah - 15 Minutes