21V Battery Rapid Charger Base, Single Port Fast Charger Compatible 21V Lithium-Ion Battery (Battery Not Included) 21V Battery Charger: Supports 100-240v universal standard AC input voltage. LED indicator light, you can easily check the charging status. 6 Fold Protection: This fast charger is equipped with overload protection, overheat protection, overcharge protection, overcurrent protection, overvoltage protection and over-discharge protection. Safer charging, extend battery life. Single Charging Port: 4000 mAh battery is fully charged in 90 minutes, 2000 mAh battery is fully charged in only 45 minutes. Save charging time and improve work efficiency. Compatible More: Our charger is compatible with some major brands, for more matching information, please contact us to inquire. Custmer Support: Fast Charger for 21V Lithium Battery come with 7*24 hour technical service. If you are not sure whether this battery is suitable for your tool, please contact us for consultation.