The MILWAUKEE® M18™ REDLITHIUM™ FORGE™ HD12.0 Battery Pack delivers 50% more power than 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 than 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.