Milwaukee's REDLITHIUM CP3.0 Starter kit provides you with 50% more power and runs 50% cooler than other M18 REDLITHIUM battery packs. This increased performance gives you the same power and runtime as an M18 REDLITHIUM XC battery in a lighter and more compact package. The 18-volt battery pack delivers fade free power and runs cooler through heavy applications, allowing you to push your cordless power tools to the limit. The REDLITHIUM HIGH OUTPUT battery is fully compatible with all 175+ Milwaukee M18 tools, while the M18 7 M12 Multi Voltage charger accepts all of Milwaukee's M12 and M18 batteries, so you'll always be prepared and productive, especially on a job that requires a mix of M12 and M18 cordless power tools. The battery charger communicates directly with your battery pack to monitor cell voltage, temperature and charge status to ensure a full charge. As an added level of communication, the chrager indicates when a lithium-ion battery reaches an 80% charge, providing you with confidence that your battery can complete a substantial amount of work without waiting for it to charge fully.