The battery is an important part of the car’s start up process. It’s also a back up source of power when a car’s requirement exceeds what the alternator can deliver. This use, coupled with time, can lead to a build up of corrosion on and around the battery terminals, and around the cable ends. To extend the life of the car and improve the power draw on the battery, the terminals must be cleaned.
WARNING: The following article on how to clean the battery cable ends and terminals is to help readers understand the mechanic’s process. This article is NOT to help the car owners do the work themselves, as battery acid can too easily spread and burn skin and eyes.
The positive cable end connects the battery to the power distribution center, which provides power to all vehicle systems. The negative cable attaches to the car’s chassis to complete the ground circuit. The car will have no power to start if either one is disconnected.
When corrosion forms it inhibits the power transfer from the battery to the vital systems. There are two reasons why corrosion forms: The cable end and terminal are made of different types of metal; and, the battery is off-gassing hydrogen during the charging process.
Corrosion looks like a crusty or fuzzy-like substance that is too easily spread. If a build up of corrosion forms between the cable ends and terminals, it can prevent the battery from delivering power. The mechanics at Hi-Tech Addison Auto Repair use several different methods to clean the connections.
Step 1: Disconnect Cables from Battery Terminals
The mechanic first disconnects the negative battery terminal using a battery cable wrench. The order of disconnection and re-connection is critical for safety. If the battery is a top post, the mechanic will only loosen the clamp tension in order to remove the cable, which might require some wiggling and prying. A side post battery requires a continuous loosening until the cable is removed.
Step 2: Clean the Battery
The cleaning process doesn’t require any unique cleaning solution, but it does require safety glasses and some household materials. The first step is to sprinkle baking soda powder onto the terminal and nearby surface. Pouring a couple tablespoons of water onto the powder will activate reactionary bubbling that can appear quite ferocious for a few seconds. The combination of the water, baking soda and corrosion forms the bubbling reaction that neutralizes the acid—making the battery safe to handle. The same steps are taken with the cable ends. Most mechanics use a small tub to contain the reactionary affects.
The chemistry is not always enough to clean the terminal or cable ends, so a wire brush is used to scrub the surface after the acid is neutralized. Once all of the corrosion is removed, clean water is used to flush the surface, terminal posts and cable ends. The mechanic then dries everything with blasts of air from the compressor. After everything is dry a thin layer of petroleum jelly, an electrical conductor, is spread between the terminal and cable ends to protect the clean surfaces from corrosion.
Step 2b: Alternative Approach
Some mechanics prefer to use special tools that accomplish the same tasks including a battery cleaner spray, battery terminal brush, a protective spray and distilled water.
Many of the sprays have a yellow dye in it that shows up purple in the presence of acid. This alerts the mechanic to areas requiring additional cleaning. However, mechanics that follow the proper procedures never get the chance to see the yellow spray turn purple. Once the evaluation is done following the spray, the battery is rinsed with water to clear all elements of the spray. Extra caution must be taken with the professional sprays, as it will stain paint from the car fender if splattered.
The battery brush is used to remove any corrosion build-up in the clamp. All contacts are then coated with a battery protector spray.
Step 3: Reconnecting Cables to Battery Terminals
Reconnecting the cable ends are critical and requires putting the positive cable on first—the opposite order from the removal process. Top post batteries may require a couple taps or wiggling to reseat the cables. The nuts on the clamp is snugged and then given an additional quarter turn.
One other step is required throughout the process and that is the inspection of the battery. If at any time there is noticeable damage or cracking of the battery housing or cables, the part must be replaced immediately and handled with extreme care during the recycling process.
Hi-Tech Addison Auto Repair always recommedns that battery cleanings are left to the professionals and not done at home. The number of battery acid injuries reported to poison control and major medical centers is staggering. While many people are aware that splattered acid can burn the skin, most are unaware at what state the battery acid could become airborne and burn mucous membranes.
Another safety consideration is the type of battery purchased. The life expectancy of original batteries is 3-4 years. A replacement Interstate Battery is good for 5 years. While $20 can be saved on a battery, the discount is only possible due to the life expectancy dropping to 3 years. Hi-Tech always recommends the extra $20 charge for the 5 year life and fully warranted battery.
—Have one of our ASE Certified Mechanics clean your battery.—