A car battery serves many purposes in a car, beyond just enabling the radio, headlights, and air conditioning. A crucial function is powering the starter motor; without a battery, starting the car will be impossible. So, how long does a car battery actually last? And what precautions should we take to extend its lifespan?
As we just mentioned, when a car is started, the battery discharges to the starter motor, which then drives the engine flywheel and crankshaft to start the car. Before the car starts, the battery powers all the electrical functions we use, such as listening to music, listening to the radio, turning on the lights, using the dashcam, and operating the electronic parking brake.
Once the engine starts, the power output from the engine will drive the generator. At this time, the voltage output by the generator will be slightly higher than that of the battery, and the battery will be charged. The power supply will then be primarily powered by the generator, with the battery as an auxiliary power source.
Our batteries actually have a very limited capacity. Leaving two 55W headlights on continuously for about five hours will drain a 12V 60A battery completely. Additionally, the starter motor puts a significant load on the battery during ignition, which is also a major factor affecting battery life.
Under normal use, a car battery's lifespan is approximately 3 years. However, if the battery is subjected to excessive power consumption, load, and duration during this period, its lifespan may be shorter. For example, what habits lead to increased battery drain? Listening to the radio in the car after turning off the engine; forgetting to turn off the headlights at night; and using external electrical devices, such as dashcams, which draw power directly from the battery – all of these reduce battery life. Frequent engine starts also place a significant instantaneous load on the battery. Therefore, many car owners with start-stop systems are concerned about battery life.
Actually, the batteries in cars with start-stop systems are quite special; they are called AGM batteries. These batteries have a cycle charging capacity that is about three times higher than that of ordinary lead-acid batteries.
The lead-acid batteries used in most of our cars have a relatively short lifespan, lasting about 2 to 3 years. However, one advantage is that the electrodes of this type of battery are made of lead and lead oxide, and the electrolyte is an aqueous solution of sulfuric acid. If the battery cannot be charged or discharged, distilled water can be added, which can extend its life by another 1 to 2 years.
Another type is called a maintenance-free battery, which sounds impressive, and it is. Its biggest advantage is that it has a longer lifespan than lead-acid batteries. It requires no maintenance and doesn't need distilled water; it's essentially disposable—just replace it when it's used up. Its lifespan is generally twice that of a regular battery.
First, we need to change our careless habits, such as forgetting to turn off the headlights after parking. Secondly, try to minimize the use of various electrical devices inside the car when the engine is off, such as the radio and headlights. Also, avoid using external electrical devices when the engine is off, as these can damage the battery and shorten its lifespan.
Which has a longer lifespan: lithium-ion batteries or lead-acid batteries?
Lithium-ion batteries are a type of battery that uses lithium metal or lithium alloys as the negative electrode material and a non-aqueous electrolyte solution. The earliest lithium metal battery was proposed and studied by Gilbert N. Lewis in 1912. In the 1970s, MS Whittingham proposed and began researching lithium-ion batteries. Due to the highly reactive chemical properties of lithium metal, its processing, storage, and use require very strict environmental controls. Therefore, lithium-ion batteries were not widely used for a long time. With the development of science and technology, lithium-ion batteries have now become mainstream.
Lead-acid batteries (VRLA) are rechargeable batteries whose electrodes are primarily made of lead and its oxides, and whose electrolyte is a sulfuric acid solution. In the discharged state, the positive electrode is primarily composed of lead dioxide, and the negative electrode is primarily composed of lead; in the charged state, both the positive and negative electrodes are primarily composed of lead sulfate.
