Intelligent microprocessor controlled with minus delta V -delta V cut-off function. Use constant current pulse charging system. Ni-MH and Ni-Cd batteries can be charge at the same time. Recharges batteries in single or group. The Unique Discharge Feature---100%protection for New NiMH or even old NiCD Batteries. Automatic charge and discharge function. Bad cell detection. Special mechanical protection against wrong polarity. Build-in maximum charging timer control for overcharge protection.