The M12 charger accepts all M12 batteries, so you will always be prepared and productive. The charger communicates directly with the battery pack to monitor cell voltage, temperature and charge status to ensure a full charge. Power up your compact batteries in 30 minutes and extend capacity batteries in 60 minutes, without the need for extra charges on the jobsite. The Milwaukee REDLITHIUM 2.0 provides up to 2X more run-time, 20 percentage more power and 2X more recharges than a standard lithium-ion battery. REDLITHIUM 2.0 also delivered best-in-class performance in extreme job-site conditions. With Milwaukee durability built into each pack, the REDLITHIUM 2.0 battery operates cooler and performs better in climates below -18-degree C/0-degree F with fade free power.