1, operate strictly according to the operation procedure. 2, check the two battery voltage, to ensure that the voltage of the two battery is the same. 3, shut down all the car load, neutral position, pull the handbrake, start the engine. Smoking is prohibited in the vicinity of the vehicle. 4, if the car battery has been frozen, prohibit the start, otherwise it may lead to an explosion. 5, please make sure the battery terminal correct polarity .