What voltage should be used to charge a car battery?
2 Answers
When charging a car battery, a voltage of 14.25 to 14.75 volts should be used. The functions of the battery are: 1. To provide a strong starting current to the starter when starting the engine; 2. To assist the generator in supplying power to electrical equipment; 3. To charge the battery when the generator's terminal voltage is higher than that of the battery. Steps for replacing the battery: 1. Remove the battery's fixing mechanism. Some batteries may have a protective casing that needs to be removed; 2. Disconnect the negative terminal of the battery. Do not disconnect the positive terminal first, as a short circuit may occur if the positive terminal touches the car body, resulting in sparks; 3. Remove the positive terminal of the battery. The positive terminal may have a protective device, so be careful to avoid damage during removal; 4. Replace the old battery, secure the new battery, install the positive terminal, and then the negative terminal.
I often charge my car battery myself, especially in winter when the battery is prone to draining. The standard charging voltage for a car battery is generally around 14 volts, depending on the battery type—conventional lead-acid batteries typically range between 13.8 and 14.4 volts, while AGM batteries may go slightly higher, up to 14.7 volts. The charging voltage must not be too high, as it can damage the battery plates, nor too low to avoid incomplete charging. I usually use a smart charger that automatically adjusts the voltage to prevent manual errors. Additionally, before charging, I check the battery's condition, such as measuring it with a voltmeter—if it reads below 12.6 volts, it needs charging. I recommend doing this in a garage or well-ventilated area, away from spark sources, as safety comes first. After each charge, the car starts much more smoothly.
