What does a battery cable do?
Battery cables are an important piece of any electrical system, as they are what directly connects the battery to vehicle's electronic system. They are usually made of heavy gauge wire covered in heavy duty insulation due to the high amount of current and power that flows through them.
Corrosion on the terminals is due to hydrogen gas being released from the acid in the battery. It mixes with other things in the atmosphere under the hood and produces the corrosion you see on the terminals. Generally, if the corrosion is occurring on the negative terminal, your system is probably undercharging.
- Problems with other sensor inputs or a defect in the control module itself may prevent the alternator from charging properly. A slipping drive belt is another common cause of undercharging, especially with V-belts on older vehicles. Alternator slippage and undercharging can also be caused by a bad alternator pulley.
- Do this with the cotton swabs or toothbrush dipped in vinegar or lemon juice. The acid from these will help dissolve the corrosion from the device. Scrub with the swab or toothbrush to remove as much corrosion as possible. Any remaining residue can be removed with baking soda and a tiny bit of water.
- Here, you will mix two tablespoons of baking soda with an equal amount of water in a clean container. Stir the solution to form a paste, then use a toothbrush to apply the paste to each terminal. The solution will begin to sizzle as it interacts with the corrosion. Use a wire brush to remove the remaining residue.
The ground is the heavy cable, normally color coded black, that attaches to the negative terminal of the battery. Anytime you are doing car work that involves electrical components, you should disconnect the ground cable from the battery first.
- By convention, this typically is where you hook the negative terminal of a battery, but that is not always the case. Strictly speaking, the negative terminal is not ground, it may be connected to ground, and so be at ground potential. In a car, negative terminal of battery is connected to chassis.
- The protective ground is green or green with yellow stripe. The neutral is white, the hot (live or active) single phase wires are black , and red in the case of a second active. Three-phase lines are red, black, and blue.
- Reconnecting the car battery – positive first. Once you're finished with the electrical work on your car, you can go ahead and replace the connectors back on to the terminals. Make sure you start the way you finished, reconnecting the positive terminal first and then the negative afterwards to prevent short circuits.
Start the dead car's engine and let it idle for a few minutes. Disconnect the black jumper cable from the once-stalled engine. Then disconnect the black jumper cable from the booster car. Remove the red jumper cable from the booster car.
- Any battery or alternator issues that affect power quality will be transmitted to your car. The good news is that large 12v batteries make excellent buffers against power issues that might otherwise cause damage. However, it is still possible to suffer damage to your car from jumping someone elses.
- A car with a "dead" (discharged) battery can be made to start by supplying it with power from an external source, such as the battery of another car. The cables used to make the necessary temporary connection are also commonly called "jumper cables". These usually are equipped at the ends with alligator clips.
- A car battery usually holds 48 amps so if you take that it charges at approximately 1 amp per hour you can work out how long it will take to charge your battery with various amperage chargers. Charging your battery with a four amp charger will take about 12 hours to get a full charge out of this low amperage.
Updated: 3rd December 2019