The Nitecore Ci4 USB-C charger is a universal intelligent charging solution for various battery types with a USB-C connection. This four-slot charger supports Li-Ion, IMR, Ni-MH, and Ni-Cd batteries with independent channel control for simultaneous charging of up to four batteries. Each slot delivers 750 mA in QC/PD mode, while single-slot operation provides 3000 mA charging power, charging a 3000 mAh battery from 30% to 80% in about 35 minutes. The charger features automatic battery detection, voltage selection, and three charging modes (CC, CV, and -dV/dt) to optimize charging performance. A special IMR battery charging program monitors the entire charging process to extend battery life. The Ci4 offers protection against reverse polarity, overcharging, and short circuits, as well as the ability to reactivate deeply discharged Li-Ion batteries with protection circuits. The USB-C connection supports reversible plug orientation and automatic QC/PD input detection, compatible with various power sources such as USB power adapters, computers, and power banks. The energy-efficient display shows real-time charging information, while the flame-retardant plastic housing and optimized heat dissipation design ensure stable charging temperatures. Input specifications include 5V/2A, 9V/2A, and 12V/1.5A with a maximum output of 18W. The output power varies by mode: QC mode provides 3000 mA (single slot), 1500 mA (two slots), 1000 mA (three slots), or 750 mA (four slots), while standard mode delivers 2000 mA, 1000 mA, 700 mA, or 500 mA. Compatible battery types include IMR/Li-Ion: 10440, 14500, 14650, 16340 (RCR123), 16650, 17350, 17500, 17650, 17670, 17700, 18350, 18490, 18500, 18650, 18700, 21700, 22500, 22650, 25500, 26500, 26650, 26700 as well as Ni-MH/Ni-Cd: AA, AAA, AAAA, C, D. Dimensions: 14.8 cm length × 10.5 cm width × 3.7 cm height.