How to Charge a Dead Car Battery
There are several reasons your car battery could die; including going for long periods of time without starting your car, 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 recharge the dead battery by transferring energy from the functional battery. Continue reading this article to learn more about the steps you can take to safely and effectively charge a dead car battery using jumper cables.
Part 1Before 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.
Goggles and gloves will protect your eyes and hands from any sulfuric acid that may eject from the battery.
If your battery cables are corroded, clean them as best as possible using a brush with stiff bristles.
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 varies greatly depending on their style and manufacturer. Do not attempt to connect two different pairs of jumper cable together if your first pair isn’t long enough. This can melt the jumper cables and start a fire.
Part 2Jump-Starting the Dead Battery
Positive terminals will be indicated by the plus symbol (+), and negative terminals will be indicated by a minus symbol(-).
The positive jumper cable is usually red in color if it is not labeled otherwise. The order in which you attach the jumper cables does make a difference, so follow this pattern: First 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.
In most cases, the negative jumper cable is black.
This will ground the car that contains the dead battery upon jump-starting. You can attach the ground cable to the frame, chassis, or another component that is reasonably clean and free of paint or oxidation.
Upon starting the engine, its charging system will begin to charge the dead car battery through the jumper cables.
This will allow the dead battery to build up a charge of its own, although it would take longer to fully charge the 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 five more minutes to pass for the dead battery to charge.
This will prevent sparks or an explosion from occurring.
Disconnect the grounding cable first, then the cable attached to the negative terminal on the battery, then the cable attached to the positive terminal of the battery of the car that provided the jump, and finally the cable attached to the positive terminal on the previously dead battery.
This will allow the alternator in the car to recharge the battery.
In some cases, your battery will become fully charged within this time period; however, it is possible that you may need to purchase a new battery for your car if the battery doesn't charge sufficiently to crank the car.