Why does the car battery light come on in rainy weather?
2 Answers
When the battery light on the car dashboard illuminates, it indicates an issue with the car battery. A yellow light suggests that the battery is low on charge or completely depleted, which can prevent the car from starting. In this case, you can use a jump-start device to start the car and let it run for a while to recharge the battery. After restarting, the yellow light should disappear, and the battery will return to normal. If the light is red, it indicates not just a battery issue but a fault in the power supply system. In this situation, it is recommended to turn off all electrical devices in the car and call for roadside assistance. The reasons for the battery light illuminating are as follows: 1. If the generator output voltage is lower than the battery voltage, the generator is not working, or there is a fault in the power supply circuit, the car battery light will come on. In this case, the generator and charging circuit should be inspected at a repair shop. 2. The battery light on the dashboard is a warning light indicating that the generator is not charging. Normally, it will light up when the ignition switch is turned to the ON position and turn off after the engine starts. If the light remains on after starting, it may indicate that the generator is not charging or there is a wiring issue, requiring inspection at a service station. If the generator fails to charge, the electrical devices in the car will rely solely on the battery during driving, and the battery will not be recharged. Once the battery is depleted, the car may stall or fail to start. 3. If the car battery is low on charge, the battery indicator light may also illuminate. However, the car can still be used in this situation, as the battery can be recharged by the generator inside the engine while driving.
When driving this car on the road, I often encounter the battery light turning on during rainy weather. This is mostly because the car has been driven for a long time, and the battery terminals have become rusty or corroded. When rainwater gets on them, it causes poor contact between the metals, leading to inefficient current transfer. At this point, the indicator light reminds me that there's an issue with the charging system. Once, during heavy rain while I was in a hurry, the light suddenly came on. I got out to check and found the terminals were wet and slightly short-circuited. I wiped them dry with a cloth, and the problem was resolved. If ignored, the alternator might not keep up with the power supply, causing the battery to drain and the car to stall on the road. So, before the rainy season, I always make it a habit to check the battery box and alternator belt to ensure they are secure and kept dry, avoiding placement too close to the bottom. Remember to turn off the engine and check as soon as possible after parking on wet roads to prevent more serious issues. After all, safety comes first—don’t let small problems turn into big ones.
