How to Jump Start a Car Safely

• Both cars off, in park or neutral, parking brakes on, not touching each other.
• Check the dead battery for cracks, leaks or a swollen case. If it is damaged or frozen, do not jump it.
• Find the correct jump points. Many modern cars have a remote positive post under a red cover and a designated ground stud — the battery itself may be in the trunk or under a seat.

That last step matters. A charging battery vents hydrogen, and the final connection can spark. Making that spark away from the battery is the whole point.

• 1. Red clamp to the positive terminal of the dead battery.
• 2. Red clamp to the positive terminal of the good battery.
• 3. Black clamp to the negative terminal of the good battery.
• 4. Black clamp to an unpainted metal ground point on the dead car's engine block or the designated ground stud — not to the dead battery's negative terminal.

Run the donor car for two or three minutes, then try the dead car. If it does not start within about ten seconds of cranking, stop and wait a minute — continuous cranking overheats the starter.

Once running, remove the clamps in the exact reverse order, then drive for at least 20–30 minutes to put meaningful charge back. A short trip will not recharge a flat battery; a proper charger will.

One flat battery is an event. Two is a fault. Have the battery load-tested, the charging voltage checked, and look for parasitic drain if the car keeps going flat overnight.