Category Archives: How cars work

How to charge a dead car battery

There are several reasons your car battery could die; including failing to start your car for long periods of time, storing it in freezing outdoor temperatures, leaving headlights or interior lights on while the car is turned off, and more.
In order to charge a dead car battery, a set of jumper cables and a functional car with a charged battery is required.
You will then have the ability to connect the batteries to one another using the jumper cables, and re-charge the dead battery by transferring energy from the functional battery.

Before Jump-Starting

  1. Make sure the battery is the problem.
  2. Inspect the physical appearance of your car’s battery before jump-starting. Your battery should be intact with no cracks, and should not visibly leak any battery acid.
    Do not attempt to jump-start your car if your battery displays signs of these damages, as you may cause injury to yourself or others if you do so.

  3. Wear safety goggles and rubber gloves before touching the dead car battery in any way. Goggles and gloves will protect your eyes and hands from any sulfuric acid that may eject from the battery.

  4. Verify that the cables attached to your car’s battery are secure and free of corrosion.
    If your battery cables are corroded, clean them as best as possible using a brush with stiff bristles.

  5. Drive the functional car into position next to the car with the dead battery without allowing the vehicles to touch one another. Ideal positions for this task are either placing the cars closely next to one another facing the same direction, or facing one another head-on, or nose-to-nose.
    Verify that the distance between each car’s battery is close enough for the jumper cables to connect the cars together. The length of jumper cables vary greatly depending on their style and manufacturer.

  6. Turn off the functional car that contains the charged battery.

Starting the car

  1. Open the hood or compartment on each vehicle in which the batteries are located.

  2. Take note of the positive and negative terminals on each battery. Positive terminals will be indicated by the plus symbol, and negative terminals will be indicated by a minus symbol.

  3. Connect each end of the positive jumper cable to the positive terminals on each car battery. The positive jumper cable is usually red in color if it is not labeled otherwise. For example, connect one end of the positive jumper cable to the dead battery, then connect the other positive end of the jumper cable to the charged battery.

  4. Connect one end of the negative jumper cable to the negative terminal on the functional, charged battery. In most cases, the negative jumper cable is black.

  5. Attach the other end of the negative jumper cable to a grounded metal component of the car that contains the dead battery. This will ground the car that contains the dead battery upon jump-starting. You can attach the ground cable to the frame, chassis, or other component that is reasonably clean and free of paint or oxidation.

  6. Start the engine of the car with the charged battery. Upon starting the engine, its charging system will begin to charge the dead car battery through the jumper cables.

  7. Allow at least 5 minutes to pass after starting the engine of the car with the charged battery. This will allow the dead battery to build up a charge of its own, although it would take longer to fully charge the battery.

  8. Try to start the engine of the car that contains the dead battery. If the jumper cables and the battery you are charging have enough power, the car engine should turn over easily and start.
    If the engine in the car with the dead battery fails to start, allow 5 more minutes to pass for the dead battery to charge.

  9. Disconnect and remove the jumper cables from each car after the engine has started in the reverse order in which you connected them. This will prevent sparks or an explosion from occurring. For example, if you connected the negative jumper cable to the battery terminal on the car with the dead battery first, remove this particular cable last.

  10. Allow the car which had the dead battery to continue running for at least another 10 minutes. This will allow the alternator in the car to recharge the battery.

    Resources:
    http://www.doityourself.com
    http://wikihow.com