Jump starting a vehicle with a dead battery using jumper cables connected to a good battery is a common roadside repair. The battery in the working vehicle provides enough electric current to start the engine in the disabled vehicle. There are important safety procedures to follow including identifying correct battery terminal locations under the hood, connecting jumper cables in the proper red to positive, black to negative sequence, taking care not to allow cable clamps to touch or sparks to occur, and monitoring batteries for signs of overheating after jump starting. Portable jump starter packs powered by lithium ion batteries have gained popularity for jump starting vehicles without requiring a second working vehicle. Professional roadside assistance technicians are properly trained on how to safely jump start vehicles of all types from small cars to trucks and heavy equipment using industry best practices to send current through the starting system without causing damage from sparks or reversed polarity.