maintenance of the electric vehicle and the combustion of the battery.
1. Do not store at a loss of electricity: the state of loss of electricity means that the battery of an electric vehicle is not charged in time after use, resulting in insufficient charging and a decrease in battery capacity. The longer the idle time in the deficient state, the more serious the battery damage. When the battery is not in use, it should be charged once a month, which can extend the battery life.
2. It is necessary to check regularly during use. If the continuous mileage of the electric bicycle suddenly drops more than ten kilometers in a short time, it is very likely that at least one battery in the battery pack has broken grids, softened plates, and activated plates. Short-circuit phenomena such as material shedding. At this time, you should go to a professional battery repair organization for inspection and repair in time.
3. Do not discharge the electric bicycle with high current. It is best to use the pedals to assist when starting, carrying people, or going uphill to avoid instantaneous high current discharge. High-current discharge can easily lead to lead sulfate crystallization, which damages the physical properties of the battery plate.
4. Master the charging time. Under normal circumstances, electric vehicle batteries are charged at night, and the average charging time is about 8 hours. If it is a shallow discharge (the mileage is short after charging), the battery will be fully charged soon, and overcharge will occur if the charging continues, which will cause the battery to heat up and reduce the battery life. Therefore, it is best to charge an electric vehicle battery with a discharge depth of 60%-70% (two bars down). It can be converted into a riding mileage in actual use, and necessary recharge according to the actual situation to avoid harmful charging.
5. Prevent high temperature exposure. An excessively high temperature environment will increase the internal pressure of the electric vehicle battery and the battery pressure limiting valve will be forced to open automatically. The direct consequence is to increase the battery's water loss, and excessive battery loss will inevitably lead to a decrease in battery activity, accelerate the softening of the plate, and charge When the shell heats up, the shell bulges, deforms and other fatal injuries.
6. Charge the battery in winter, keep it indoors, and warm the battery for two hours before charging.
As the time of use, the battery of electric vehicles is not far away from Vietnam. This is normal, especially in cold weather. Generally, the battery needs to be charged once when 70-80% of the electricity is used. The so-called full charge means waiting. After changing the lamp, it can be charged for about 2 hours to ensure that the battery is fully charged and reaches the best mileage. Generally, there is a deep discharge in about two months, that is, it can be recharged with empty to achieve the phenomenon of lead precipitation and improve the battery’s performance. Capacity, the most feared is that the battery of an electric vehicle is often used when it is empty or the light is not changed when it is charged. It should be fully charged once if it is not used for a long time about 20 days.
7. Parking environment
Under normal circumstances, the battery of an electric car is with the car. The quality of the parking environment also has a certain impact on the battery. The electric car should be kept as ventilated and dry as possible. Because the humid environment will cause electric vehicle battery leakage, so as to shorten the battery life.
8. Charger maintenance
When it comes to charging electric vehicles, the first thing to use is electric vehicle chargers. Protecting the charger is a very important step. Nowadays, the cost of electric vehicles is relatively low, and the shock-proof performance of the charger is not very good. Many people like to put the charger in the trunk or basket of the electric vehicle. In fact, this behavior is very bad. Because the electric vehicle charger will drift the internal electrical potentiometer after long-term vibration, making the charging parameters become abnormal, the battery life will be shortened when the charging time is long with such a charger. In addition, the charger must be charged. Ensure good ventilation to ensure good heat dissipation.
9. Pay attention to frequent maintenance
Many electric car dealers will provide free after-sales maintenance services, which can be regularly inspected and maintained. For example, the lack of battery electrolyzed water can only be discovered during maintenance. Measures such as timely water replenishment are also very important for battery maintenance.
10. Charge every day
Many people have a certain misunderstanding about how long electric vehicles should be charged, thinking that they should wait until the electric vehicle battery is completely used up before charging. In fact, this is also wrong. Current electric vehicle batteries generally use lead-acid batteries, and their memory capacity is not very strong, but often discharged batteries will have a greater impact on the battery. Daily charging makes the battery power in a shallow cycle state to make the battery life of electric vehicles longer.
11. Regular deep discharge
As mentioned earlier, electric vehicles should be charged every day as much as possible. However, reasonable regular deep discharge is also beneficial to "activate" the battery. Generally one to two months deep discharge is the most reasonable. The specific method is to charge the electric bike when it is under-voltage indicated. Note that after riding to undervoltage, the electric bike will recover part of its power after a period of time. Do not ride it again at this time, otherwise the battery will be very damaged.
12. Good cycling habits
I talked about the precautions for charging electric vehicles, now I will talk about the issues that need to be paid attention to when riding a bicycle. There is a principle to be mastered when riding a bicycle, start slowly and stop slowly. Specifically, the flow should be slow when starting, and try to avoid sudden braking. Because the electric load is the largest when the electric vehicle starts and brakes suddenly, frequent unstable current will reduce the life of the electric vehicle battery.
How to avoid the problem of coating dark marks on lithium batteries
The coating process of the lithium battery is to coat the slurry on the current collector, and drying is to remove all the solvent in the slurry. Lithium battery pole piece coating is more prone to dark marks, streaks and coating wrinkles, which is obviously different from general coating coating: the slurry wet coating is thicker, the slurry is a Newtonian high-viscosity fluid, and the fluid flow is The required shear stress changes with the change of the flow rate. It is difficult to adjust the coating thickness according to a standard method, which is also a difficulty in the coating process of the coater. It requires very high levels of operator proficiency and experience.
Lithium battery coating dark mark
The accuracy of the pole piece coating is very high, and the thickness deviation is about 3um, so the equipment is very demanding.
(1) To ensure the consistency of coating as much as possible, pay attention to the change of slurry viscosity, the change of liquid level on the hopper, and the change of coating speed during operation;
(2) The thin layer of slurry on the aluminum foil is dried in the oven to remove the NMP solvent (NMP boiling point is 202°C, flash point is 95°C). If drying is too slow, the coating surface has fluidity, the thickness is unstable, and the drying is too fast. PVDF film is formed on the surface. The volatilization of the internal NMP solvent will cause the surface layer to wrinkle. In order to ensure uniform evaporation of NMP, segmented drying is usually used. The middle section has the highest temperature. The positive electrode is generally 100-130℃, if the negative electrode adopts an aqueous system, the drying temperature is generally 75-90℃; in the drying process, NMP volatilizes, and the composition of the coating slurry is constantly changing, so the amount of NMP solvent in the preparation of the slurry and the temperature rise The method and heating time have an influence on this;
(3) The heating temperature or time is not enough, it is difficult to remove the liquid in the slurry, so that part of the binder is dissolved, causing the active material to peel off; if the heating temperature is too high, the binder will crystallize and the active material will also peel off. Cause a short circuit in the battery core. In addition, inappropriate drying temperature and drying time will also cause oxidation of the aluminum foil and wet pole pieces;
(4) Coating and drying must be the first three inspections-thickness, quality, size meet the requirements, and regularly inspect the corresponding drawing speed, baking time, gap, etc.
Lithium battery coating dark mark
Explanation about coating streaks and dark marks:
The dark marks are caused by uneven thickness on the surface of the pole piece during coating, and the appearance of dark marks appears. The uneven thickness may be caused by (1) the surface thickness of the pole piece is uneven due to foreign matter on the knife edge or uneven surface of the knife edge (with gaps) during the drawing process; (2) before or after rolling There are linear traces. It is mostly caused by particles that have not opened the knife edge or a small dry slurry stuck on the knife edge.