Winter Maintenance Guide for Electric Vehicle Lithium Batteries
For batteries, the focus is often on capacity and energy density, and these data can often intuitively reflect the length of cruising range. But what we should note is that most batteries are electrochemical products. Since it is related to chemistry, its performance has a great relationship with temperature. Let’s first look at the effect of temperature on battery performance through data.
The capacity of the battery is most closely related to the cruising range. How much does temperature affect the battery capacity? It can be seen that when the discharge current is 100A, the battery capacity shrinks by 1.7% and 7.7% respectively from 20°C to 0°C and then to -20°C. This means that even if the temperature is as low as -20°C, the battery can still reach more than 90% of the nominal capacity. It can be said that the effect of temperature on battery capacity is relatively small. However, this does not mean that we can ignore the effect of temperature on the battery. According to the information provided by experts, under the condition that the charging current is 5A, the charging time at the ambient temperature of -25℃ is 63% slower than the charging time at 25℃.
Battery life is also a concern. According to the data, if a battery with a capacity of 3500mAh works in an environment of -10°C, after less than 100 charge and discharge cycles, the power will rapidly decay to 500mAh, and it will basically be scrapped. That is to say, in a working environment of -10°C, if you charge and discharge once, the battery will be scrapped and replaced after three months. This figure may be a bit exaggerated, but low temperatures do drastically shorten battery life.
Therefore, regarding the impact of low temperature on the battery, the conclusion is that although the low temperature environment has little effect on the discharge performance of the battery, it will seriously affect the charging performance of the battery and greatly shorten the life of the battery.
There are two main aspects to the battery technology winter solution for low temperature environment, one is the progress of battery technology, and the other is the maintenance of electric vehicle battery in winter.
For electric vehicle lithium battery maintenance methods in winter: In addition to relying on the technological progress of lithium battery factories, consumers can also perform winter maintenance of electric vehicle batteries through some simple methods. So how do you go about doing it? First, pay attention to the charging method, try not to charge the battery under low temperature conditions, and the same is true for high temperatures. When the high temperature exceeds 30 °C, the charging needs to increase the current input. Second, when charging in winter, you can use the method of charging several times. When the battery is charged, you can charge more at one time. Third, maintain a full power state. In winter, when the battery discharge exceeds 50%, the electrolyte will be in danger of freezing. Therefore, in winter, the battery should try to keep it above 50% of the power. Fourth, every other period Time to start the car, charge it, don’t let the battery discharge too much, don’t let the electric car sit outside for too long in the winter. In this way, I believe that our lithium battery electric vehicle will be safe this winter.