Battery is the heart of electric vehicle, and it is the decisive factor and key part of the driving mileage of electric vehicle. Therefore, it is necessary to have some knowledge of the battery before purchasing electric vehicles, so as to purchase the suitable walking tools.

At present, the electric vehicle batteries on the market are generally lead-acid batteries and lithium-ion batteries.

Lead acid battery is also called lead acid battery. Since the invention of lead-acid battery, because of its low price, easy access to raw materials, reliable performance, easy recovery and suitable for large current discharge, it has become the world's largest production and widely used battery. After more than 100 years of development, the lead-acid battery has been widely used in automobile, communication, electric power, railway, electric vehicle and other fields.

Lead acid battery has low cost and high cost performance. Most of the commercialized e-bikes are sealed lead-acid batteries, which do not need to add water frequently and are maintenance free. Therefore, lead-acid battery is also a popular electric vehicle battery.

The charge and discharge process of lead-acid battery is the process of electrochemical reaction, in which lead sulfate is a very easy to crystallize material. When the concentration of lead sulfate in the electrolytic solution of the battery is too high or the static idle time is too long, small crystals will form. These small crystals will attract the surrounding lead sulfate again, just like snowballs, to form large inert crystals. When the crystallized lead sulfate is charged, it can not be reduced to lead oxide, but also precipitated on the electrode plate, resulting in the decrease of the working area of the electrode plate. This phenomenon is called vulcanization, which is often called aging. At this time, the battery capacity will gradually decrease until it can not be used.

That's why many car owners complain about the short life of lead-acid batteries.

However, lithium-ion battery has the advantages of high specific energy, high specific power and small self discharge, no memory effect, good cycle characteristics, fast discharge, high efficiency, wide working temperature range and no environmental pollution. It is currently a battery with high specific energy, small volume and light weight. Lithium battery is also the research and development direction of electric vehicle enterprises. The newly launched electric vehicles are basically equipped with lithium batteries or high-profile lithium batteries.

1. Compared with ordinary batteries, lithium batteries are much smaller and lighter. Generally, the same type of lithium battery is only half the size of lead-acid battery, and its weight is one third of that of lead-acid battery.

2. The life span of lithium battery is generally about 5 to 6 years, and the warranty period is generally about 3 years, which is much longer than that of ordinary battery with only one year or one and a half, so it is not necessary to worry about whether to replace the battery every year, and the annual use cost of lithium battery used by consumers is about 100 yuan lower than that of ordinary electric vehicle.

3. The lithium battery of the lithium battery electric vehicle is safer than the ordinary battery. There are qualitative differences between the lithium battery and other ordinary batteries. When there is heavy pressure, impact, short circuit and other situations, the lithium battery will not explode.

4. Compared with ordinary battery, lithium battery is more green and has little environmental pollution, because long service life can avoid environmental pollution caused by replacement of ordinary battery.

5. Because of its small size and low weight, lithium battery electric vehicles are generally light and beautiful, easy to move, and many can be folded.

6. When charging ordinary lead-acid battery electric vehicles, consumers always worry about the memory effect of batteries. When using lithium batteries, everyone can relax. Lithium batteries do not have memory effect.

Note: in the use of lithium battery electric vehicles, it should be noted that the battery will enter the sleep state after a period of time, when the capacity is lower than the normal value, the use time will also be shortened. Therefore, we should learn to maintain lithium battery electric vehicles