You connect the red positive cable to the dead battery's positive terminal first, then the other red clamp to the good battery's positive terminal. Next, connect the black negative cable to the good battery's negative terminal, and finally, attach the last black clamp to an unpainted metal surface on the dead car's engine block or chassis—not the dead battery itself. This sequence prevents dangerous sparks near the battery, which can emit explosive hydrogen gas.
The key is the final connection point for the black clamp. A car's battery is grounded to its chassis. By clamping to bare metal, you are completing the circuit without risking a spark directly at the depleted battery, which is the potential danger zone. A bolt on the engine block, a bracket, or even a clean nut works perfectly.
Here’s a quick reference for the correct order:
| Step | Cable Color | Connect To: | Why It's Important |
|---|
| 1 | Red (+) | Dead Battery's Positive Terminal | Establishes the positive circuit path. |
| 2 | Red (+) | Good Battery's Positive Terminal | Links the power source. |
| 3 | Black (-) | Good Battery's Negative Terminal | Completes the circuit on the donor side. |
| 4 | Black (-) | Unpainted Metal on Dead Car's Engine/Chassis | Provides a safe ground, avoiding sparks at the dead battery. |
Once connected, start the donor car, let it run for a few minutes, then try starting the dead car. After a successful jump, remove the cables in the reverse order: black from the ground on the dead car, black from the donor battery, red from the donor battery, and finally, red from the previously dead battery. Drive the jumped car for at least 15-20 minutes to allow the alternator to recharge the battery.
