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When removing a car battery, should the positive or negative terminal be disconnected first?

2 Answers
StLucy
07/25/25 12:03am
When removing a car battery, disconnect the negative terminal first, then the positive terminal. The installation process is the opposite: connect the positive terminal first, followed by the negative terminal. Inspect the battery before replacement: Before replacing the battery, check if it is completely depleted. If the battery is cracked, replace it immediately. If not, inspect both terminals of the battery, as sulfate buildup can sometimes corrode the battery terminals. Turn off the car before replacement: Carefully loosen the battery screw connected to the negative terminal using a wrench, remove the cable clamp from the terminal, and then follow the same procedure for the positive terminal. Firmly grasp the battery and remove it from the car. Replace the battery: Carefully place the new battery in the battery tray, ensuring the positive and negative terminals are correctly positioned. Secure the battery by tightening the bracket, connect the positive cable clamp, then the negative one, and finally close the hood.
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ReaganLynn
08/10/25 3:36pm
I remember that time in the garage when I disconnected the battery, casually removing the positive terminal first. As soon as my tool touched the car body, sparks flew everywhere! I almost set the whole garage on fire. Since then, I always disconnect the negative terminal first during maintenance because it's directly connected to the metal parts of the car body, which serves as the ground path. If a tool touches both the positive terminal and the car body simultaneously, it causes a short circuit—sparks fly wildly, potentially leading to explosions or damaging the vehicle's electronic components. Newbies, take note: After turning off the engine, always disconnect the negative terminal first (usually black or marked with a minus sign)—loosen the nut and gently pull it off. Then handle the positive terminal (red or marked with a plus sign). After finishing, use some soda water to clean any corrosion from the terminals. When reconnecting, reverse the order—positive first, then negative. This method is safe, efficient, and extends battery life. Never cut corners on this procedure!
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