What Are the Causes of Car Battery Failure?
2 Answers
Car battery failure is caused by short circuits, open circuits, and reverse polarity. The detailed explanations for car battery failure are as follows: 1. Short circuit: One or multiple cells inside the battery form a discharge circuit, with a voltage around 10V or below, causing the plates to bend and deform, leading to contact short circuits between the positive and negative plates. 2. Open circuit: The connection between single cells of the battery or the terminal leads is broken. A voltmeter check shows no voltage, and the terminal posts or plate group components are poorly welded. 3. Reverse polarity: The entire battery or one of its cells experiences polarity reversal. After adding electrolyte to a new battery, the open-circuit voltage is only around 8V, or the voltage becomes negative, indicating assembly issues or manufacturing defects.
From my daily driving experience, I've found that there are several main causes of car battery failure. The most common is natural battery aging—after three to five years of use, internal resistance increases and charging capacity declines. Another major issue is forgetting to turn off headlights or the audio system, leading to excessive battery discharge. A few deep discharges can severely shorten its lifespan. Temperature also plays a role: summer heat accelerates electrolyte evaporation, while winter sub-zero temperatures make starting difficult or even cause complete failure. Long-term vehicle inactivity also results in excessive self-discharge. It's recommended to check electrode connections every six months, clean corrosion, and ensure stable battery condition. Proper maintenance can extend battery life by two to three years.
