What Causes Car Battery Overcharging?

Updated February 21, 2017

The battery supplies power to several car parts such as the headlights, dashboard, indicators, music system and air conditioning. A battery has to be recharged regularly to maintain its energy. This occurs when you turn the vehicle on and the battery gets power. However, sometimes a battery can become overcharged, which leads to leaking.


When the regulator is not set properly, the battery can easily become overcharged. Every kind of battery has a different set charge that must be administered. When a battery is charged, the regulator allows you to set the right power. The right power level for the battery depends on the vehicle make. Consult your vehicle's manual to find the appropriate level for the regulator and for specific instructions on setting the regulator for your vehicle, as each vehicle is different.

Alternator Problems

The alternator supplies power to the battery when the engine is in motion. Gas goes from the gas tank to the crankshift to the alternator via a fan belt, causing the alternator to turn. This process converts the power from the gasoline into power that the battery can use to make the car run. Often, when the alternator is not functioning properly, is out of place or doesn't have the right voltage (usually 12 volt) connected to the battery, it can cause battery overcharge. To determine if an alternator problem is causing battery overcharge, you can purchase a voltage meter from an auto supply store and check the voltage of the alternator. This should read around 14 volts, and if it does not, then your alternator may cause battery problems. Alternator problems are difficult to fix and you may want to take the car to the mechanic who can recommend repair or a new alternator.

Poor Quality Battery Charge

Poor quality battery chargers are another prime reason for batteries to overcharge. While high quality chargers supply only the charge needed; cheap chargers can cause a surge of power into the battery, causing the battery to become flooded with charge (electrolytes) which may then leak from the battery. To avoid this problem, use only high quality chargers. Galt Home Buying Guides recommend chargers by reputable brand such as Black and Decker, Sears and Diehard. Galt suggests prices for a quality charger can range from £22 to £94.20

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About the Author

Alexis Writing has many years of freelance writing experience. She has written for a variety of online destinations, including She holds a Bachelor of Arts in communication from the University of Rochester.