Where are the common leakage points in small cars?
2 Answers
Common causes of electrical leakage include: Battery short circuit or aging: When a battery has been in use for an extended period, especially in vehicles that have been operating for four or five years without replacement, the active material inside the battery gradually deteriorates. This can lead to short circuits in the battery plates, resulting in self-discharge and power loss—commonly known as battery leakage. This is the most prevalent type of leakage issue. Damage to vehicle electronic equipment: Cars are equipped with numerous sensors, wiring harnesses, and electrical components. If any of these electronic parts malfunction, particularly due to internal circuit grounding or short circuits, it can cause electrical leakage and subsequently drain the battery.
I've encountered several car battery drain issues, and the most common culprit is the battery itself leaking electricity—internal short circuits or corroded terminals can cause self-discharge as it ages. Another frequent offender is the alternator in the charging system; if its diodes fail or insulation deteriorates, it may reverse-leak current abnormally back into the battery. Additionally, aftermarket installations like alarms or dashcams often drain power, especially when left improperly switched on. My advice: start troubleshooting these areas by measuring parasitic drain with a multimeter overnight—excessive leakage rapidly depletes the battery, making engine cranking difficult. Regular battery maintenance and health checks can prevent such headaches.
