Nitecore D4 is a universal smart charger compatible with almost all cylindrical rechargeable batteries meaning you won’t have to carry around multiple chargers. The display clearly shows battery status for each individual battery (up to four batteries). Each slot can then be selected for further information on the battery its charging, a helpful feature for identifying any dud batteries or seeing which batteries have more charge. The charge time is also displayed so once you’ve charged a battery you’ll know how long it takes to charge in the future. The D4 will automatically cut off once the battery is fully charged although it is recommended you remove the battery once it is fully charged. This is an extremely advanced charger and a must have piece of kit.