Jump-start a car only when both vehicle manuals permit it and you can identify the specified connection points. These steps concern conventional compatible 12-volt systems, not an EV traction battery.
Prepare before connecting
Park safely with the vehicles not touching, apply parking brakes and switch off as directed by the manuals. Keep cables away from belts and fans. Do not proceed with a leaking, swollen, frozen or visibly damaged battery, damaged leads or an unsafe roadside position. Do not assume a hybrid or EV may act as the donor.
Connect and start
Where the manuals specify the common negative-ground procedure: connect red to the disabled vehicle’s marked positive point, red to donor positive, black to donor negative and the final black clamp to the disabled vehicle’s designated ground away from the battery. Follow the manuals for donor operation, waiting time and starting attempts. Stop if cables heat up or the vehicle does not respond as expected.
After the start
Remove leads in the prescribed reverse order, keeping clamps apart. A successful start does not prove the battery is healthy or fully charged. Arrange a battery and charging-system check if the cause is unclear; repeated jumping is not a repair.
