Can The Electric Bicycle Lithium Battery Really Last For 4 To 5 Years?

Nowadays, electric bicycles are becoming more and more high-end and intelligent. The R&D and manufacturing technology of electric bicycles is constantly improving, and the manufacturing process is also improving.

Gradually mature. However, there is a shortcoming that has always restricted the development of electric vehicles, and that is the core of electric bicycles-"lithium batteries"!

Our country's high and new technology is constantly developing and innovating. In the field of lithium battery R&D and application, lithium batteries have quickly occupied half of the battery types by virtue of various advantages, and have become the main force in the power market and energy storage products. The development of lithium batteries is inevitable. At present, the popularity of lithium batteries in the energy storage market has been very extensive. Take the battery as a comparison. Lithium batteries have advantages both in terms of weight and volume. Many people are worried about the life of lithium batteries, because the lifespan of lead-acid batteries (abbreviated to batteries) generally ends in about 3 years, so consumers are more concerned about the life of lithium batteries.

"Lithium battery" is a type of battery that uses lithium metal or lithium alloy as the negative electrode material and uses a non-aqueous electrolyte solution. Due to the very active chemical properties of lithium metal, the processing, storage and use of lithium metal have very high environmental requirements. Therefore, lithium batteries have not been used for a long time. With the development of science and technology, lithium batteries have now become the mainstream. In theory, the cycle life of "lithium batteries" is about 600 times. Please see below for details!

Can the life of an electric bicycle lithium battery last up to 5 years?

The correct statement: whether the life of a lithium battery can be used for 5 years is related to the number of completions of the charging cycle, and not directly related to the number of charging. Simple understanding, for example, a lithium battery used only half of its power on the first day, and then fully charged it. If the situation persists the next day, that is, use half of the charge and charge it twice in total. This can only be counted as one charging cycle, not two. Therefore, it may usually take several times to complete a cycle. Every time a charging cycle is completed, the power will decrease a bit. However, the reduction is very small. High-quality batteries will still retain 80% of the original power after charging for many cycles. Many lithium-powered products are still used as usual after three or four years. This is the reason. Of course, the life of the lithium battery needs to be replaced in the end.

As mentioned above, the theoretical life of a lithium battery is generally about 600 charging cycles. Assuming that the power provided by a complete discharge is Q, if the reduction in power after each charging cycle is not considered, the lithium battery can provide or supplement a total of about 600Q of power during its life. From this we know that if you charge 1/2 each time, you can charge about 1000 times; if you charge 1/3 each time, you can charge about 1500 times. By analogy, if it is charged randomly, the number of times is variable. In short, no matter how it is charged, it is constant to add a total of about 600Q of electricity. Therefore, we can also understand it this way: the life of a lithium battery is related to the total charge capacity of the battery, and has nothing to do with the number of recharges. Deep discharge and deep charge and shallow discharge and shallow charge have little difference in the impact on the life of the lithium battery.

In fact, shallow charging and shallow charging are more beneficial to lithium batteries. Only when the product's power module is calibrated for lithium batteries, it is necessary to deep discharge and deep charge. Therefore, products powered by lithium batteries do not need to be constrained by the process. Everything is convenient and can be charged at any time without worrying about affecting the lifespan.

The loss of lithium battery capacity can be expressed in the process of lithium battery charge and discharge and self-discharge:

1. Each time a complete cycle of the lithium battery increases, the charging time will decrease a little. The charging platform of the lithium battery is between 3.7V and 4.2V. The charging capacity at this stage accounts for more than 90% of the total charging capacity. As the number of cycles increases, the voltage rise speeds up, and the capacity of the lithium battery will decrease after being fully charged.

2. The discharge platform of the lithium battery is 4.1V~2.75V (the minimum discharge voltage of a single-cell lithium battery is 2.75V), and the discharge capacity at this stage accounts for more than 90% of the total capacity. As the number of cycles increases, the discharge of the lithium battery As the platform decreases, the discharge capacity also decreases.

3. The proportion of the self-discharge of the lithium battery to the total power of the lithium battery increases with the increase of the number of cycles, but the discharge platform of the lithium battery is accelerated and reduced.

The decrease in the life of lithium-ion batteries is manifested by the characteristics of capacity decline: the life of lithium batteries is ultimately limited, which is the same as the development of everything. Capacity decline is a manifestation of quantitative change to qualitative change. It can be seen from this performance that the methods to extend the life of lithium batteries are undoubtedly considered from the perspective of scientific charging and discharging and reducing self-discharge. The loss during use will directly affect the life of the battery.

If you want to maximize the life of lithium batteries, consumers must understand the three taboos of "lithium batteries"!

First, temperature: Lithium batteries are afraid of high temperatures.

Second, high current: For example, the 18650 battery is 3C discharge, your electric car is 8000W, and the battery used is lower than the discharge current of your electric car, which will cause the lithium battery to have too high temperature, too much current and shorter life. , There will be bulging scraps. If your electric car is very powerful and fast, it is recommended to choose 18650 batteries with 10C current. It is obviously very important to choose the right batteries!

Third, storage at full power: Take ternary lithium for example, the full power is 4.35V. At present, the protection boards on the market are all 4.2V and stop charging, so many people buy lithium batteries for electric vehicles and say that there is no nominal rating. The large capacity is actually for this reason. Generally, it is best to store the lithium battery of an electric car for a long time, and it is best to charge 50% of the TV. For example, if you buy a new mobile phone, most of it is 50% of the power when it is turned on. If the battery is fully charged and stored for a long time, the capacity of the lithium battery will be reduced. Except for lithium iron phosphate and lithium titanate, these two types can be stored at full charge. It is also necessary to pay attention to choosing a better quality protection board. The biggest taboo of lithium batteries is overshoot and overdischarge, and ternary lithium can be overdischarged at one time. Scrap, overshoot must be scrapped.

Pay attention to the above points, your electric bicycle "lithium battery" can be used for 4~5 years.