How To Clean And Charge A Car Battery

Car batteries are prone to building up acid deposits over time and lose their initial charge. Here's how to clean and recharge a typical car battery.

If you've ever removed an old dry cell battery from a flashlight or child's toy, you should be familiar with the idea of 'acid condensation'. A chemical battery is a combination of different metals suspended in an acidic solution. Even if the toy or flashlight or vehicle is not drawing power, the chemical reaction between these elements continues. Eventually, the acid will leak through the container and form a harsh deposit. This is a very noticeable and potentially very harmful problem when dealing with a battery as large as the one in your vehicle.

In order to properly clean a car battery, you'll want to get rubber gloves and a pair of safety glasses for personal protection. If the corrosion is especially bad, you'll also want to remove the battery from the car. The acid condensation can damage paint, so use extreme caution while moving a corroded battery. Always have a supply of clean water around to wash off any excess corrosion that may come in contact with sensitive areas or exposed skin.

Other items you will need to clean a car battery are clean cloths, commercial liquid cleaner in a spray bottle, baking soda, kitchen baster and old brushes. There are also specialized tools and cleaners available at auto parts stores which are designed to clean clamps and cables leading to the battery. One inexpensive but effective tool looks like an oversized thimble with dozens of stiff wires wrapped inside. This is a terminal cleaner, which will help remove corrosion and also expose a new layer of the terminal posts.



Now that you have your essential equipment, it's time to actually clean the battery. Make a solution of baking soda and water, and use a kitchen baster to spread this solution liberally over all areas of acid build-up. Because car batteries use sulfuric acid, a base chemical must be used to neutralize the acidity. Baking soda is a basic element, so the combination of acid and base renders the acid condensation harmlessly neutral. What you'll want to avoid at all costs, however, is accidentally pouring the baking soda solution into any open cell. This will damage the battery by weakening the acidic reaction which creates power.

Once the baking soda solution has had time to penetrate the corrosion, you may now use old brushes and water to remove the residue. You'll definitely want to wear rubber gloves and eye protection during this process. For surface dirt, try using a commercial liquid cleaner in a spray bottle. Use liberal amounts of water to wash away the build-up released by the brushes. Clean shop towels or old rags should be used to dry the battery and remove any remaining residue in crevices. As a final step, use the terminal cleaning tool to create a good contact for the cables. Cables and clamps should also be cleaned with the baking soda solution and brushes.

The other problem with an aging car battery is maintaining a charge. If a battery is allowed to run down beyond its normal operating limits, you'll need to recharge it. Recharging any chemical battery requires specialized equipment designed to SLOWLY introduce electrical current back into the dead cells. Consumers can buy decent battery rechargers at auto parts stores or retail stores with automotive departments. These units are not prohibitively expensive and can be lifesavers if a car battery dies unexpectedly. If home use is not a practical solution, then a dead battery can be brought into a service station or car dealership for a professional recharging. Be aware that a standard recharging session can last for hours, so you may want to drop off your car battery early in the morning and pick it back up in the late afternoon or evening.

To recharge a car battery, the battery charger must be plugged into a standard electrical outlet and brought to the vehicle or battery itself. This means you'll need to protect both charger and battery from the elements and keep them dry and stable. For safety's sake, it's often preferable to remove the battery from the car and place it in a low-traffic area with plenty of ventilation. Explosions caused by recharging are very rare, but gases can build up as a side effect of the charging process.

A battery charger will have two clamps- one marked positive (+) and the other marked negative (-). Usually red denotes a positive terminal, and black denotes a negative one. Make sure you know which clamp is which before you even approach the battery. Attach the negative clamp of the charger to the negative post of the battery. This information should be imprinted on the casing near the terminal. Only attach negative to negative. Once the negative clamp has been attached, then attach the positive in the same manner. Make sure the charger is set for 'charge,' and turn on the current. The actual charging process will take several hours- the charger may have indicators showing the voltage level or an automatic sensor which will cut off electrical power once the battery has been fully charged. Once the charging period has ended, disconnect the charger from the power source, and carefully remove the clamps one at a time. You should now have a fully charged battery ready to be returned to the engine compartment.

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