D4 Digicharger is a quality charger is a universal smart charger, making it compatible with almost any cylindrical rechargeable battery. This feature eliminates owning several chargers for different batteries you own. The advanced charger detects the type of battery inserted, the status of its charge, and begins the charging process. Not to be outdone, this charger can also charge four batteries at once, cutting-down your charging time. The Nitecore D4 Digicharger is an innovative charger providing you with a fully-automatic digital charge. Once your battery is fully charged, the Nitecore D4 Digicharger automatically stops charging for you and your batteryÃ¢â€žÂ¢s safety. The automatic charging feature prevents your battery from overheating and preserves your charger all at once. This all-in-one charger is equipped with LED lighting showing the charging progress, charging current, charging time and words in large, clear print for easy readability.