The PARD single battery charger is designed to efficiently and quickly charge the PARD Li-Ion 3200mAh, 3.7V 18650 & 21700 batteries. The battery compartment is spring-loaded, so the battery stays in place while charging. The integrated power indicator will signify when the batteries are fully charged. The PARD battery charger also features a built-in charging protection feature that eliminates the risk of overcharging the Lithium Ion battery. PARD 1 Slot Battery Charger Compact Fast Charging for 21700 Batteries and Accessories