You may need to disconnect your battery for several reasons. Whether to prevent the battery from suffering from damage when going on a long trip or for maintenance or replacement reasons, disconnecting a battery is a simple process that can be completed without visiting an auto shop. Still, you may be exposed to certain hazards or cause damage to the battery or car if you do not follow the correct process when disconnecting and reconnecting the battery.
How to Disconnect a Car Battery
Before disconnecting a car battery, you must confirm that you have the requisite tools and are able to correctly identify the battery. You need specific tools such as a wrench kit, pliers, protective gloves, protective goggles, and any specific tool that may be required per your car manufacturer's manual. The battery is usually in the form of a rectangular shaped box with two terminals (positive and negative) sticking out of it. The positive terminal is typically red with a plus (+) sign on top, while the negative terminal may be colored black or blue and has a (-) sign on top. By looking at the plastic caps on the battery terminals, you can identify each terminal.
Before disconnecting a car battery, you must get the car ready for the process by putting the vehicle in park position and switching off the ignition. Other precautionary measures may be required as detailed in your owner’s manual.
Which Battery Terminal to Disconnect When Working on a Car
When disconnecting a car battery, you should remove the negative terminal first. In a car system, the negative terminal of the battery is usually directly connected to the engine, body, and chassis of the vehicle, while the positive battery terminal is connected to the alternator, starter, and fuse boxes. Hence, removing the positive terminal first can result in a situation where a tool touching the body or engine can create a short circuit by shorting out against the positive terminal of the battery.
What Is The Order to Disconnect a Car Battery
Once you have the necessary tools ready, it is time to prepare your vehicle for the battery removal process. When disconnecting a car battery, put the car park and engage the emergency brake. Turn off the ignition and remove the car keys. It is unsafe to attempt disconnecting your car's battery while the vehicle is powered on. Doing so may cause car damage and bodily harm. After your vehicle is prepped, put on your safety goggles and gloves.
To locate the battery, check the hood of the vehicle or its trunk. Although some manufacturers place the battery in the trunk area, most vehicles house the battery under the hood. If you have trouble locating your car battery, check your owner's manual for more information.
After locating the battery in the hood or trunk of your vehicle, remove the caps on the terminals if they are still in position. Then, place a wrench that fits the nuts and bolts of the battery terminals on the negative terminal's nut and turn the nut counterclockwise in a loosening action. Be sure to use a snug-fitting socket when loosening the terminal to avoid damaging the nut.
After loosening the negative terminal's nut, remove the connector cable attached to the terminal from the battery and push it far aside. This connector cable must be completely out of the way and not come in contact with the battery until you are ready to reconnect the old battery or connect a new one. In a case where the cable is attached to the battery tray, you may need a battery removal tool to completely disengage the negative connector.
Upon removing the connector cable from the negative terminal, repeat the exact process for the positive terminal. You must ensure that the connector cable for the positive terminal is also far out of the way and not in contact with the battery. While turning the wrench in a counterclockwise manner, ensure it does not touch both of the terminals to avoid sparks. Furthermore, refrain from touching the wrench to metal parts of the car as a metal part can ground and lead to circuit damage to the car's electronic system
Tips for Reconnecting the Battery
Before reconnecting your battery, inspect its terminals for dirt or corrosion. If there is dirt or corrosion on any of the terminals, clean them with a mixture of baking soda and water. Dip a toothbrush in the baking soda and water mixture and gently scrub the cables and terminals to remove any built-up dirt. Rinse the terminals with clean water and dry them afterward.
To reconnect the terminals, start with the positive terminal and then the negative terminal. Secure and tighten the positive terminal's connector cable on the positive terminal using a wrench. Ensure the positive terminal is snugly attached to prevent a loose connection. Repeat the same process for the negative terminal. Connecting the positive terminal first is recommended because it reduces the risk of short circuits. If you connect the positive terminal first, you reduce the chances of accidentally creating a short circuit with a metal tool while connecting the negative terminal. Consequently, you can prevent sparks and potential damage to the electrical system of the vehicle.
Is It Safe to Disconnect a Car Battery?
While it is generally considered safe to disconnect a car's battery, you should check with your manufacturer's manual to learn what the recommended process is. Removing a car battery may cause problems such as loss of air conditioning, false warning lights, electronic module damage, and power accessory malfunctions.
With many modern cars fitted with a powertrain control module (PCM), disconnecting the battery in a car can cause memory loss as the PCM forgets its adaptive memory settings. These settings contain the adjustments learned over time by the PCM for transmission shift points, fuel mixture, and other control functions. This may lead to the car functioning poorly until the PCM relearns its adjustments, which may take a few days or several miles of driving.
Conclusion
Disconnecting a car battery is usually a DIY process if you have the necessary tools and follow recommended safety measures. You would need a wrench and protective wear like gloves and goggles. Start by disconnecting the negative terminals before the positive terminal to avoid potential hazards. When reconnecting the terminals, reverse the process by connecting the positive terminals first. Doing this helps remove the odds of a short circuit and prevents sparks.
While disconnecting a car battery is a relatively simple process, potential hazards for removing your car's battery include power accessory malfunctions arising from loss of PCM adaptive memory settings. Still, if you are going on a long trip without your car, it is recommended that you disconnect your car's battery. When disconnecting your battery, refer to the vehicle's manual for specific instructions or seek professional help from your auto mechanic if you are not sure about the process.
