What is the proper way to jump start a car from another car?
The reason why you connect the battery cables to the dead car battery first is you have 3 metal cable ends dangling and potentially touching metal car parts, so a dead battery is less likely to cause any sparking, since it has little or no voltage. So that is the safest starting point for your jumper cables. The 2nd battery cable clamp goes to the positive end of the good battery instead to minimize completing any circuits until we are ready to. Then the 3rd end of the battery cable goes to the ground of the good battery. Remember, we still have not completed the circuit yet, until the 4th battery cable clamp is attached to ground. This is why this order of attaching the battery cables to your car batteries is the safest way to do it. It minimizes unnecessary sparking until the charging circuit is completed. This is good practice because excessive and unnecessary sparking could cause car batteries to fail. Since the bad battery is weak, and to prevent exploding, it’s ground clamp gets
