Nitecore i4 battery charger bundle with Four NL188 18650 3100mAh Batteries The Intellicharge i4 is a universal, automatic smart-charger compatible with almost all types of rechargeable batteries thus eliminating the need to own several chargers. The i4 is able to automatically identify Li-ion, Ni-MH and Ni-Cd rechargeable batteries and apply an appropriate charging mode (Constant Charge Current (CC), Constant Charge Voltage (CV) and Trickle Charge). Each of the i4's four microcomputer-controlled charging slots is capable of monitoring and charging batteries independently. Additionally, yellow and blue power/charging status indicator lights could visibly indicate battery status and charging process. Features middot;Capable of charging 4 batteries simultaneously middot;Each of the four battery slots monitors and charges independently middot;Compatible with and identifies Li-ion (26650, 22650, 18650, 17670, 18490, 17500, 18350, 16340(RCR123), 14500, 10440), Ni-MH and Ni-Cd (AA, AAA, AAAA, C) rechargeable batteries middot;Optimized charging design for IMR batteries middot;Automatically detects battery status and selects the appropriate voltage and charge mode middot;3 Color LED displays charging progress for each battery middot;Automatically stops charging when complete middot;Features over-charge prevention to protect batteries middot;Features temperature monitoring to prevent overheating middot;Features reverse polarity protection middot;Designed for optimal heat dissipation -12V in-car adapter included 2 X Nitecore NL188 18650 3100mAH Batteries Capacity: 3100mAH Voltage : 3.7v Protected: Yes Size : Diameter 18.6mm ; Length 70mm 2X EdisonBright AA to D battery converter spacers included. Spacers allow use of rechargeable AA batteries in D battery equipment.