Nitecore D4 Digi charger is a universal smart charger compatible with almost all cylindrical rechargeable batteries. D4 comes four independent microcomputer-controlled charging channels and capable to monitor and charge up to four batteries simultaneously. It is fully automated that it detects the battery type, selects the appropriate charging mode and stops when it completes. Its crystal-clear LED screen displays the real time charging mode, progress. Nitecore D4 is truly the world's most advanced fully automated digital charger. It's as simple as insert, detect and charge.