man taking battery out of car

If you’re ever in a situation where you must remove the battery from your vehicle, it’s important to know what you’re doing. It seems pretty straight forward, and it is. However, there are some important things to remember when disconnecting the battery in your car, truck, or SUV. Here are some tips on disconnecting a car battery, from Harold's Used Auto Parts Inc in Philadelphia, PA.

Why would you need to disconnect a battery? - There are multiple reasons that warrant disconnecting a battery from a vehicle. Replacing the battery if the current battery is bad, charging or testing a dead battery, to clean the battery terminals, working on an electrical system, or resetting an electrical system are all possible reasons to disconnect a battery.

Safety First! - A 12V battery won’t shock you as a wall outlet will. However, there are still risks involved, and they should be taken seriously. Never handle a leaking battery. Battery acid is explosive, and highly corrosive, which makes it capable of causing bad chemical burns. Let a professional technician deal with it, don’t fight with the terminals. If the terminal can't be removed from the post, have a professional handle it. Prying or twisting the post will likely cause it to break off inside the battery - this will definitely cause a leak, ruin the battery, and could even cause it to explode.

How Do You Remove a Battery? - It depends on the vehicle, but most batteries are easily accessible. On some models, the battery may be in the trunk, or you might have to remove a wheel first. Disconnect the negative terminal (black terminal) first. When disconnecting a battery, the wrench you use to loosen the terminal will likely contact something else in the process. You still need to be careful not to let the wrench hit the positive post or any live wires, but typically live wires are well insulated. Once the negative terminal is disconnected, the positive terminal won’t transmit current to ground if you accidentally knock something metal while removing it. If you try to remove the positive terminal first, anything metal on the vehicle is a potential ground, and touching the wrench to the ground even for a split second isn’t a good situation to be in. You might fry electronics, or get burned - the wrench will heat up quickly, hot enough even to melt it, and sometimes will even weld to the point of contact making it impossible to remove. In short, just pull the negative terminal first. It’ll avoid the risk of getting burned, starting a fire, or damaging the vehicle. Safety glasses are a good idea. Make sure you loosen the nut holding it tight with the right size wrench or socket to avoid stripping it. Remove the strap that holds the battery in place. You may need an extension to do this. Don’t do this first - it increases the chance of grounding the positive terminal. Remove the positive terminal. Inspect the battery for leaks before you touch it then lift the battery out, maintaining a firm grasp, and set it in a safe location where nothing can contact the posts. It’ll be fairly heavy. They are durable, but you certainly don’t want to drop it - it could break the case and cause battery acid to escape or splash onto your skin.

To install/replace the battery, just go in reverse, being sure to connect the negative cable last. Be sure to clean the terminals and the posts of any corrosion or grime before installing them. There are special tools for that, but a wire brush or a piece of sandpaper works just fine. Just be cautious, take your time, and follow these instructions. Of course, if you don’t feel comfortable handling a battery or run into trouble along the way, we’re here to help.

You can purchase a battery, have it installed, and the old one disposed of right here, saving you the trouble and leaving you confident it was done right. For the best auto service shop in Philadelphia, PA, call or stop by Harold's Used Auto Parts Inc today.



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5347 Whitby Ave
        Philadelphia, PA

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