How to Use the Jump Start Cables

During your lifetime of driving, there will probably be at least one point where you’ll need to start a car with a dead battery. And besides attempting a push start, using jump-start cables is an easy option, but there are several steps that should be followed.

About the Jump Start Cables

Jumpstart cables are an essential part of any tool kit. They are usually made of two thick insulated copper wires, one red and one black, and they have a claw style connector at each end. Jumpstart cables are relatively inexpensive, but they can save you from an expensive tow call out.

Steps to Start a Car with Jump Start Cables

  1. Align the vehicles – have the vehicles positioned so that there is the shortest distance between the two batteries. Jumpstart cables are often only about 1.5m in length, and if you have the battery on the far side of each car it is likely that they won’t reach.
  2. Examine the jump start cables – check for any worn spots in the cable’s insulation. This could lead to a connection not being made. You can use electrical tape to make small repairs, but for larger ones, you should replace the cables.
  3. Turn off the ignitions – make sure that the ignition is off in both cars. If they are on, you may see sparks when connecting the cable and this could start a fire.
  4. Connect the positive cable (red) – connect the positive cable to the positive terminal (usually red or marked with a ‘+’) on the donor car’s battery and then to the positive terminal on the dead car’s battery.
  5. Connect the negative cable (black) donor car - connect the negative cable to the negative terminal (usually black or marked with a ‘-’) on the donor car’s battery.
  6. Connect the negative cable to the dead car – connect the other end of the negative cable to the donor car. It is best practise not to use the terminal on the battery, but rather a bare metal part of the car body.
  7. Visually check that everything is connected properly – give all the jump start cable clamps a check to make sure they are secure and not going to slip off. The cars will move a little when they start and if the cable falls off it may cause damage to either vehicle.
  8. Start the donor car – turn the ignition and start the car. Let it idle for a few minutes, you can pump the accelerator a little to get the engine moving a little faster. It is during the idle phase that the car will charge the dead car’s battery.
  9. Start the dead car – after a few minutes trying to start the dead car. How long the battery has been dead will determine how long the donor car needs to idle to be effective. If the car doesn’t start when it is turned over, you’ll need to let the donor car idles longer.
  10. After a successful start – once the dead car has been started let both cars idle for a few minutes and then remove the jump start cable in the reverse order.
  • Disconnect the negative cable from the dead car
  • Disconnect the negative cable from the donor car
  • Remove the positive cable from the dead car, replace any battery covers
  • Remove the positive cable from the donor car, replace any battery covers
  • Move the donor car to a safe distance

Be careful that you don’t touch the ends of the cable together or drop one of the cables into the moving engine.

11. Drive the newly revived car – while it is up and running drive the dead car for a few kilometres. This will help charge
the battery so it will start again after being turned off. If you don’t do this step it is likely that the small charge the
battery has will dissipate by the time you need to start the car again.

Jump Start Cable Safety Tips

Using jump start cables is relatively easy, but as with any job involving moving engines there are a few safety tips that should be adhered to:

  • Examine the battery on the dead car if it is damaged in any way, then do not attempt to use jump start cables. Examine the battery posts, check that they are not loose. The pan the battery sits on should be dry, if there is a liquid, the battery may be leaking. These are all signs that the battery should be replaced.
  • If you need to buy jump-start cables, get the best ones you can afford. Having good quality clamps will stop the cables from slipping. Thicker gauge wires will conduct the charge better and not heat up.
  • Don’t allow live cable ends to touch, the computer system in many newer cars can be quite sensitive to power shocks.
  • Wear protective equipment, especially gloves. Don’t wear loose clothing, remove any jewellery and tie back your hair if it is long.
  • If you are not confident using jump-start cables have an experienced person show you or call a mobile mechanic.