Cell phone lithium battery decays after 2 years. Why do pure electric vehicle batteries have a longer warranty practice?

With the continuous development of automobile industry, the number of pure electric vehicles is also increasing. The difference between pure electric vehicles and traditional fuel vehicles is that the power source is the battery pack, not the fuel engine. The ternary lithium batteries or lithium iron phosphate batteries carried by pure electric vehicles are all liquid lithium-ion batteries, and the mobile phone batteries we usually use are also lithium batteries. So why does the lithium battery carried by pure electric vehicles have a longer life, while the mobile phone decays after 2 years?

Although both of these batteries are lithium batteries, there are still some differences. Lithium batteries carried by mobile phones are generally small in size, and the discharge current per unit time is also small. The power battery is not, because the power battery needs to drive the vehicle forward, so the discharge current per unit time is large. In the battery industry, power batteries use double-layered bipolar tabs as a unit, or use multiple bodies as a unit to increase the current of the whole battery pack. The battery capacity is affected by the output current, so the direct function of parallel connection is to increase the capacity of power lithium battery pack. However, the battery capacity connected in this way is often large, and the continuous discharge time is long because of the large internal resistance and small discharge current.

In addition, there are some differences between the two batteries in terms of their own and product safety. The protection of mobile phone battery for products is relatively small, and most of them are the safety design of the battery itself. The high value of power battery will affect the driving safety, so the power battery has high safety protection. Many power batteries have protection circuits, heat dissipation and so on. At present, battery BMS management system is also widely used.

Finally, the battery carried by the mobile phone does not need long-term reliability, so there is not much requirement for consistency. Moreover, the mobile phone itself is a fast-moving consumer product, and the update is faster than the car. In addition, the price of mobile phones is relatively low, so even if the lithium battery decays and needs to be replaced, consumers' acceptance is higher. The power battery carried by pure electric vehicles is expensive, and if it is replaced frequently, the acceptance of consumers will be relatively low. Therefore, the service life of mobile phone lithium battery is short, and the service life of pure electric vehicle power battery is long.

This article comes from car home, the author of the car manufacturer, and does not represent car home's position.