Use the right technique: Proceed with caution. If you fail to correctly follow the instructions and method described here, you could jeopardize your safety — and boosting efforts.
- Make sure the two vehicles are not touching.
- The dead battery must not be frozen. Wavy battery walls are generally a sign that the battery is frozen.
- Be sure the two batteries are of the same voltage.
- Remember, batteries give off hydrogen, an explosive gas. Avoid sparks and open flames. Smokers beware!
- Avoid getting battery electrolyte in the eyes or on skin, clothing, and painted surfaces. Electrolyte is a corrosive sulphuric acid solution that can cause serious burns. In case of contact with electrolyte, immediately rinse the affected area with a lot of water.
- Wear work gloves. It is recommended that you wear the appropriate safety glasses when working around batteries, and remove any rings, metallic bracelets, or other jewelry.
- Engage the parking brake. Put the gear shift in neutral (manual transmission) and depress the clutch, even if it is not usually required to start your car, or shift to “park” for an automatic transmission. Remember to turn off all electric accessories (lights, heater, air conditioner, etc.).
Begin the boosting procedure
- Start the engine of the healthy car.
- Attach one red booster cable clamp to the positive terminal (+) on the dead battery.
- Attach the other red cable clamp to the positive terminal (+) on the healthy battery.
- Attach one black cable clamp to the negative terminal (-) on the healthy battery.
- Attach the other black cable clamp to the engine block or another major metal component of the engine—like the alternator frame—of the disabled car. This connection should be made at least 30 cm (1 foot) away from the battery to avoid sparks, which can cause an explosion. Do not attach the booster cable to the ground terminal of the dead battery.
- Try to start the vehicle with the dead battery, following the instructions in the owner’s manual for cold-weather starting. Do not crank the engine for more than 15 seconds at a time or you may damage it (on some models, a device cuts the starter off automatically after this amount of time).
- Remove the cables in reverse order.
Warning: Not following the instructions for jump starting may cause serious injury. CAA-Quebec shall not be held responsible for injury or damage resulting from following this method.
Give it time to recharge
If the engine makes no sound whatsoever when you try to start it, the battery is completely dead.
Contrary to popular belief, it is important to leave the cables hooked up to both running vehicles for at least 5 minutes to allow the weak battery time to recharge; this also lessens the risk of overvoltage. Be aware that there is always a risk of a momentary voltage surge once the booster cables are disconnected. This can damage the car’s electrical system and radio. Once the disabled vehicle is running again, it is recommended that you turn on the heating and defrost systems to prevent any damage in the event of overvoltage.