From The National Safety Council:

Jump-Starting a Weak or Dead Automobile Battery Correctly



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When a motor vehicle battery fails, a jump start often is the best short term way to get the motor going. Because it is important that jump starting be done properly, the National Safety Council recommends the following procedure:

  • Position another vehicle with a healthy battery and your car so they do not touch each other. Be sure both batteries are of the same voltage.
  • Read the owners’ manuals for BOTH vehicles for any special directions.
  • Turn off the ignitions of both vehicles and set the parking brakes. Place automatic transmissions in “Park” and standard transmissions in neutral.
  • Wear safety glasses and gloves while using cables.

Unless given different directions in the owner’s manual, use the booster cables in this order:

  • Clamp/connect one end of the positive (+) booster cable to the positive (+) post of the dead battery.
  • Connect the other end of the same cable to the same marked post (+) of the booster battery.
  • Connect the second, negative (-) booster cable to the other post of the booster battery.
  • Make the final negative (-) booster cable connection on the engine block of the stalled vehicle away from the battery.
  • Start the booster vehicle and let it run for a few minutes. Then, start the disabled vehicle.
  • Remove the cables in the reverse order of connection, being very careful not to let the booster cable clamps touch each other or some in contact with car parts. Also, avoid the fans of the engine. Electric fans may run without the engine being on.

Information and recommendations are compiled from sources believed to be reliable. The National Safety Council makes no guarantee as to and assumes no responsibility for the correctness, sufficiency or completeness of such information or recommendations. Other or additional safety measures may be required under particular circumstances.