What Are the Causes of Electric Vehicle Battery Degradation?
3 Answers
Electric vehicle battery degradation may be caused by increased internal resistance and battery management. Increased Internal Resistance: Internal resistance is an important parameter for measuring battery performance. However, since electric vehicles operate with higher currents, internal resistance has a greater impact on power batteries. It is also influenced by many factors, such as the battery's materials and manufacturing processes. Besides internal resistance, battery management is another key factor affecting battery performance. Good battery management can significantly reduce performance degradation and improve cell consistency. Correct Usage of Electric Vehicle Batteries: Lithium-ion batteries in electric vehicles do not require any special activation method; they naturally activate during use. Deliberately using the widely circulated "12-hour long initial charge activation" method is futile and ineffective. When the battery shows a low-power warning during operation, it should be charged as soon as possible. Not all claims about fully discharging the battery before charging or prolonged charging are correct—it depends on the battery type. Charging should follow standard time and procedures, even for the first three charges. With various lithium battery products on the market, it is advisable to choose high-quality, reputable brand batteries.
I believe there are several main reasons for electric vehicle battery degradation. Firstly, the natural aging of internal chemical reactions in the battery, such as the gradual decomposition of electrode materials in lithium-ion batteries during repeated charging and discharging, leads to capacity reduction. Over time, the electrolyte also deteriorates, increasing resistance and reducing battery efficiency. Secondly, overcharging or deep discharging causes significant damage. If you frequently drain the battery completely or charge it to 100% full capacity, it accelerates the degradation of battery cells as they are not designed for extreme conditions. Thirdly, high temperatures are a silent killer. For example, parking under direct sunlight in summer causes cabin temperatures to soar, and elevated battery temperatures can trigger thermal runaway, permanently reducing performance. Additionally, batteries have limited charge cycles - each vehicle has approximately several thousand charge-discharge cycles, and frequent use of fast charging with high current accelerates structural fatigue. From years of research, I understand that while battery management systems can mitigate some effects, natural degradation is inevitable. I recommend maintaining charge levels between 20-80%, using slow charging instead of fast charging to slow this process, and conducting regular health checks to identify issues early.
As an electric vehicle owner, I believe the degradation is mainly caused by usage habits. If you frequently use fast charging, the battery suffers from high-voltage current impacts and rapid temperature rises, leading to faster capacity loss over time. Additionally, frequent deep discharges—like always waiting until the battery drops to 5% before charging—accelerate cell damage, as it's designed for shallow charge-discharge cycles. Temperature is also crucial: battery performance declines in cold winters, but prolonged high temperatures are worse, such as parking outdoors without a garage where summer heat can damage internal components. My neighbor’s car lost significant range after two years because it was often used in hot weather. Aging is another factor: batteries degrade over time like smartphones, though better manufacturing slows this process—losing 2-3% capacity annually under normal use is typical. To mitigate degradation, I schedule charging at night when temperatures are lower, avoid full charges, drive regularly to keep the battery active, and never leave it idle for too long.
