Why Does a Car Always Have Electricity?
2 Answers
Generally, a car only uses the electricity from the battery during the starting phase. Once the engine is running, whether the vehicle is idling or in motion, the generator remains operational, continuously charging the battery. Precautions for using a car battery are as follows: Keep it clean: Maintain the battery clean and dry, ensuring the vent holes are unobstructed. If oxides appear on the plates or terminals, clean them and apply a small amount of grease to prevent corrosion. Avoid continuous use of the starter: Each use should not exceed 5 seconds, with a 10~15-second break between two starts. In severe winter, the battery discharge level should not exceed 25%, and in summer, it should not exceed 50%. Regular charging: A battery filled with electrolyte should not be left in a state of insufficient charge for long periods. Regular charging is necessary; otherwise, it may lead to battery failure. Charging standards: When charging the battery, the voltage should not be too low or too high. Typically, the standard charging voltage for a 12V battery is within the range of (13.5~14.5)V, and for a 24V battery, it is within (28~29.9)V.
This is a pretty common issue. I usually drive the family car to work and noticed that even after turning off the engine, the clock on the dashboard stays lit, and the preset radio stations aren’t lost. At first, I thought it was some kind of malfunction, but the mechanic later explained to me that the car remains powered because it has a main battery, like a big power bank, which continues to supply small electrical devices when parked. These devices include the anti-theft system, the remote key receiver module, and the ECU computer’s memory function. Without this continuous power supply, you’d have to reset the time or codes every time you drive, which would be a hassle. However, it’s worth noting that older car batteries might not last long. My friend’s old SUV once couldn’t start because the battery drained after sitting idle for too long. So, he advised me to at least take a short drive every week to let the alternator recharge the battery or use a maintenance charger to keep the battery level up, avoiding sudden power loss that could affect safety.
