Widely compatible, Ni-MH/ Ni-CD can be charged. The XTAR X4 extended version can charge not only 3.6V /3.7V 14500-26650 Li-ion batteries, but also 1.2V Ni-MH and Ni-CD batteries. It can satisfy 99%  users' needs include charging protected 20700 and 21700 batteries. Auto-selected current for speedy charging. It intelligently selects the charging current among 0.5A *2, 1A *2 and 2A * 1, and fully charges two 18650 2500mAh batteries in 1.5 hours with 2A*2 current. Dual input ports for freely charging With AC input port and Micro USB input port, you can choose a suitable one in different scenarios: powered by the power cord and AC input port indoors, or mobile phone adapter and Micro USB port for outdoors charging.