How to Jump-Start a Car
By the Super Simple Digital Tools Team · Updated June 2026 · Medium · 15 minutes
A dead battery is the most common reason a car won't start, especially in cold weather or after leaving lights on. With jumper cables and a running vehicle you can be back on the road in minutes — as long as you connect the cables in the right order.
⚠ Safety: Never let the clamps touch each other while connected, and keep them clear of moving engine parts. Connecting the order wrong can spark near battery gases.
Steps
- Position the cars. Park the working car close enough for the cables to reach, but not touching. Turn both engines off and set the parking brakes.
- Connect the positives. Clip one red clamp to the positive (+) terminal of the dead battery, and the other red clamp to the positive terminal of the good battery.
- Connect the ground. Clip one black clamp to the negative (−) terminal of the good battery. Clip the other black clamp to a bare, unpainted metal bolt on the dead car's engine block — not the battery.
- Start the cars. Start the working car and let it run for 2–3 minutes. Then try to start the dead car.
- Remove cables in reverse. Once it starts, remove the clamps in the exact reverse order (black-engine, black-good, red-good, red-dead). Keep the revived car running for 20+ minutes.
Tips
- If it won't start after a few tries, the battery may be beyond a jump and need replacing.
- Drive for at least 20 minutes afterwards to let the alternator recharge the battery.