The MILWAUKEE M18 REDLITHIUM FORGE HD12.0 Battery Pack delivers 50% more power vs the HIGH OUTPUT 12.0, and the longest life vs REDLITHIUM batteries. REDLITHIUM FORGE are Milwaukee's most powerful, fastest charging, and longest life batteries. The M18 REDLITHIUM FORGE HD12.0 delivers 12 amp hours of runtime with 50% more power vs the HIGH OUTPUT 12.0, providing optimal power and runtime for demanding applications. This lithium-ion battery has the longest life, the most recharges, and the best performance over the life of the battery. It is also designed with resistant housing for increased protection against exposure to common oils, greases, and solvents. Built-in REDLINK Intelligence protects the battery from overloads, preventing you from damaging your cordless power tools in heavy-duty situations. The REDLITHIUM FORGE HD12.0 battery is fully compatible with 275+ M18 solutions. Our M18 & M12 Rapid Charger charges battery packs up to 40% faster, reducing your downtime and maximizing your productivity. The battery charger accepts all MILWAUKEE M18 and M12 batteries, providing a charging upgrade for both systems. The battery charger communicates directly with your battery pack to monitor cell voltage, temperature, and charge status to ensure a full charge.