20V MAX Li-Ion batteries from a vehicle's power outlet, enabling batteries to be charged while driving to work or on a job site. It charges the battery in 1 hour or less thus minimizing downtime. It has an automatic shut-off feature that protects against excessive discharge of vehicle's battery. It also has built-in diagnostics with LED indicators that communicates battery charge status: charged, charging, power line problem, replace pack, and battery too hot or too cold