What is the voltage of a car battery?
2 Answers
Car batteries typically operate between 11.8 volts and 12.8 volts. The correct charging method for a car battery is as follows: 1. Connect the positive terminal of the battery to the positive terminal of the power source and the negative terminal to the negative terminal; 2. Charge until the electrolyte releases bubbles and the single-cell voltage rises to 2.3 to 2.4 volts, then stop; 3. Reduce the charging current to half; 4. Measure the single-cell voltage until it reaches 2.7 volts, indicating the charging is complete. A car battery consists of plate groups, separators, electrolyte, casing, terminals, connecting straps, and filler cap. Maintenance tips for car batteries include: 1. Avoid parking the car in open parking lots for extended periods; 2. In winter, avoid repeatedly starting the car without intervals; 3. Regularly charge the car battery; 4. Periodically clean the battery terminals and apply grease to protect the wiring harness.
The voltage of a car battery is generally a 12-volt system. I drive a lot, and most common sedans are designed with 12V batteries. During startup, the voltage should be above 12 volts to be considered normal. If the battery has been left unused for a long time, the voltage may drop to 11 volts or even lower, making it difficult to start the car. Remember to use a multimeter to check the voltage: when fully charged, it should be between 12.6 and 12.8 volts; if it drops below 12.4 volts, it’s time to recharge; if it falls below 11.8 volts, the battery might be dead and need replacement. Don’t overlook the battery terminals during routine maintenance—dirt buildup can corrode the connections and cause poor contact. The average lifespan of a car battery is about 3 years. In winter, voltage fluctuations are more significant due to low temperatures, so it’s best to check in advance to prevent issues. Why do cars use 12V? It dates back to the old days—early cars used a 6-volt system, but as electronic devices became more common, 12 volts proved more efficient and stable. Today, it also accommodates various lighting and air conditioning needs. If you experience slow starts or dim lights, prioritize checking the voltage before driving carelessly—safety always comes first.
