There are two main factors that affect the lifespan of new energy vehicle batteries: the number of charging cycles and time. In addition, there are several secondary factors: average charge and discharge power, battery storage and operating temperature, and depth of charge and discharge.
1. Number of charging cycles
Under ideal conditions, a typical PHEV can withstand 1000-2000 charging cycles while retaining over 70% of its usable capacity. For a PHEV, the range per cycle is generally 50-80 kilometers, meaning it can typically travel around 100,000 kilometers on pure electric power before the battery fails. However, since PHEVs often utilize hybrid power for much of their range, the actual range is more dependent on the number of charging cycles. Regardless, PHEV batteries have smaller capacities, resulting in a shorter lifespan. Theoretically, the usable lifespan of a PHEV private car is approximately 5-10 years.
2. Usage time
Generally, lithium batteries can last up to 10 years with proper maintenance. However, the lifespan becomes more uncertain due to various maintenance issues and the degradation of the battery's active materials. Based on practical experience, lithium batteries with proper storage conditions can easily exceed 10 years of calendar life, but 20 years or more is questionable.
3. Average charging and discharging power
In short: fast charging affects battery life. How much of an impact? Small. But it does have an effect. According to various automotive news reports, if a BEV is charged 80% by fast charging and 80% by slow charging, the battery will degrade slightly faster with the former, but not significantly. Battery industry professionals have also stated that slow charging is beneficial to battery life, but the impact of fast charging is not as significant as imagined. During the normal lifespan of a vehicle, the difference between the two is not substantial.
4. Battery storage and operating temperature
Temperature also has a significant impact on battery life. If the battery operates below 0 degrees Celsius or above 40 degrees Celsius for a long time, it will accelerate battery aging and capacity decay, and this decay is irreversible [2]. Fortunately, most new energy vehicles today are equipped with battery temperature control systems, which enable the battery pack to operate at a more suitable temperature.
5. Depth of charge/discharge
While this impact on battery life is a secondary factor, it can potentially cause fatal damage to the battery during use. Although lithium batteries have a long lifespan, they cannot withstand over-discharge, especially deep discharge. What is deep discharge? It means using the battery to below 5%, or even below 0%. Deep discharge is like starving a normal person for a day or two. Starving for a day or two won't kill you quickly, but doing it long-term has a significant impact on health. If you keep the battery below 5% without charging it for an extended period, the battery will be "starved" to death, with no hope of recovery. If you leave it uncharged for half a month after deep discharge, rest assured, the battery's lifespan will immediately end. However, under normal circumstances, no one would do this. It is recommended to maintain a charge/discharge range above 20%; if you occasionally use it below 10%, charging it promptly is generally not a problem.
Therefore, under normal use, the battery life of a PHEV is 5-10 years, and that of a BEV is 10-20 years. The larger the battery capacity and the longer the pure electric driving range, the longer the battery life.
