How to Tighten Car Battery Terminals

March 21, 2024

If you're experiencing a loss of power, erratic headlights or a difficult time starting your car, the cause may be loose battery terminal connections. A loose connection can prevent the transfer of electricity from the positive and negative terminals, resulting in weaker electrical currents that drain your battery. Fortunately, loose terminals are an easy fix. Open the hood of your car and locate the battery, located on the passenger side or near the front of the engine bay. The battery will be large and rectangular in shape. Use an adjustable wrench or screwdriver to remove the cover on the battery. Look for two metal posts on the top of the battery labeled with a negative symbol (-) and a positive symbol (+).

Use a wrench to disconnect the terminal nut from the negative post, moving the cable out of the way without stretching it. Repeat with the positive terminal and cable.

Once the cables are disconnected, wipe away any dirt or corrosion on both terminals. A light application of baking soda and water is also useful for removing any built-up corrosion. Alternatively, you can use a metal-cleaning solvent for more severe build-up. Regularly popping the hood and inspecting your battery will help you maintain a tight connection, keeping the internals of your car battery safe and efficient.

Once your car is back together, reconnect the positive cable first. Ensure that the terminal connector sits as far down on the positive terminal as possible and is tightened so that you can't move it by hand. Then reconnect the negative cable, ensuring that the terminal connector doesn't touch any part of the positive terminal or any other metal parts of the car or engine.


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