How to Check the Battery Level of a Car?
3 Answers
We cannot see the exact battery level of a car, but we can determine whether the battery has power by observing certain phenomena. More accurately, we can assess the state of the battery. On the outer surface of the battery, there is an observation hole called the "battery eye," which helps determine the battery's condition. When the display shows green or blue, the battery is in good condition. If it shows black or red, the battery needs charging. A white display indicates insufficient electrolyte, which means the battery needs replacement. The simplest and most straightforward method is to feel the feedback when starting the car. If the ignition feels particularly difficult, it is likely that the battery is out of power. Of course, there’s no need to worry too much. After normal driving for one to two hours, the battery will usually return to a normal level. Another indicator is the battery fault light. If this light stays on, it indicates that the car’s battery is almost out of power, and immediate charging is required. When the emergency jump starter battery runs out of power, recharge it fully. Afterward, you can test how many times the emergency jump starter can start a car. Additionally, you can use a mobile phone to test how many full charges the emergency jump starter can provide when the phone’s battery is at zero.
I usually drive an older gasoline-powered car, and I mainly rely on the dashboard to check the battery status. Before starting the car, I pay attention to the voltmeter—around 12 volts is healthy, while below 11 volts might indicate the battery is nearing the end of its life. The most obvious sign is when starting the vehicle; if the engine struggles to turn over, it's likely due to a weak battery. At night, before getting out of the car, I make it a habit to check the brightness of the headlights—if they appear dim, it’s a clear sign of low battery. Last winter, the voltage dropped significantly, and the next day the car wouldn’t start at all, forcing me to call for a jump-start. Now, I’ve developed a habit of opening the hood every month to check for corrosion on the battery terminals—it saves a lot of trouble.
Having been into car modifications for over a decade, the most practical upgrade I've made is installing a voltmeter below the left side of the steering wheel. It allows me to monitor real-time voltage while driving. In traffic jams when engine RPM is low, the voltage fluctuates around 13 volts. If it goes above 14 volts, it indicates overcharging. Keeping a multimeter handy is also crucial - after turning off the engine, check the battery terminals; if it reads below 12.4 volts, it's time to recharge. Last time I helped a neighbor check, his car showed only 11.8 volts when off, clearly indicating a faulty voltage regulator. Friends who modify audio systems should pay special attention to this, as high-power equipment drains batteries rapidly. Always keep an emergency jump starter as a safety precaution.
