RIDGID introduces the AC9540 18V 4.0 Ah MAX Output Battery and Charger Starter Kit. MAX Output Batteries are RIDGID's most powerful and longest running batteries. The included RIDGID MAX Output 4.0 Ah battery will provide up to 3X more runtime compared to the 1.5 Ah lithium-ion battery (AC870015). Pair MAX Output batteries with RIDGID tools for maximum power in any application. The RIDGID MAX Output 4.0 Ah battery is compact and lightweight, which reduces user fatigue. The included 18V Fast Charger is 2X faster than the 18V Compact Charger (AC86093) and can charge the 4.0 Ah battery in under one hour. As always, the RIDGID 18V 4.0 Ah MAX Output Starter Kit is 100% compatible with all RIDGID 18V tools and chargers. The RIDGID AC9540 includes an 18V 4.0 Ah MAX Output Battery, an 18V Charger, and an operator's manual. Battery: MAX Output Batteries provide up to 2X more power compared to the 1.5 Ah lithium-ion battery (AC870015) Battery: Up to 3X more runtime compared to the 1.5 Ah lithium-ion battery (AC870015) Battery: Advanced electronics and innovative cooling technology for extended battery life Battery: Compact size reduces user fatigue Battery: Fuel gauge displays power level on the job Charger: 5.0 Amp charge rate for 2X faster charging compared to the 18V Compact Charger (AC86093) Charger: Charges both RIDGID Ni-Cd and Lithium-Ion batteries Charger: Temperature indicator shows if battery is either too hot or too cold to charge 100% Compatible: Works with all RIDGID 18V Batteries, Tools, and Chargers