The following contents are reposted:
Q&A on battery knowledge of electric vehicles
An electric vehicle user asked: How do users use batteries to extend their service life?
A: Experienced users know that the cost of battery is the biggest consumption of electric bicycle, so users are very concerned about extending the service life of battery. First of all, it should be assumed that there is no problem with the charger, and whether the user uses it correctly is very important for the life of the battery. Precautions for using the battery are as follows:
1, don't change the charger casually, and don't dismantle the controller for speed limit.
Chargers from various manufacturers generally have personalized requirements, so don't change chargers at will under uncertain circumstances. If the mileage is required to be long, it is necessary to equip multiple chargers for charging in different places, so the charger for recharging during the day is supplemented by another charger, and the original charger is used at night. Canceling the speed limit of the controller can improve the speed of some cars, which will not only reduce the safety of cars, but also reduce the service life of batteries.
2. Protect the charger.
There are instructions on protecting the charger in the general instruction manual. Many users don't have the habit of reading the instructions, and often think of looking for the instructions after the problems appear, which is often too late, so it is very necessary to read the instructions first. In order to reduce the cost, the current chargers are basically not designed with high vibration resistance, so don't put the chargers in the trunk and basket of electric bicycles. It must be moved under special circumstances, and the charger should be packed with foam plastic to prevent vibration and bump. After many chargers vibrate, the internal potentiometer will drift, making the whole parameter drift, resulting in abnormal charging state. In addition, keep the charger ventilated when charging, otherwise it will not only affect the life of the charger, but also affect the charging state due to thermal drift. This will damage the battery. So it is also important to protect the charger.
3. charge every day.
Even if your continuous running ability is not long, you can use it for 2 to 3 days on a single charge, but it is recommended that you charge it every day, so that the battery will be in a shallow cycle and its life will be extended. Some early mobile phone users think that it is best to recharge the battery after it is basically used up. This view is wrong. The memory benefit of lead-acid batteries is not so strong. Frequent discharge has a great influence on battery life. Most chargers may charge 97% ~ 99% of the battery after the indicator light becomes full. Although only 1% ~ 3% of the battery is under-charged, the impact on the ability to continue driving is almost negligible, but it will also form under-charged accumulation, so it is also beneficial to continue floating charging as much as possible after fully charging the battery with the electric variable lamp.
4. Charge in time.
After the battery was discharged, the vulcanization process began, and obvious vulcanization occurred in 12 hours. If the battery is charged in time, trace sulfide can be removed. If not charged in time, these sulfide crystals will accumulate and gradually form coarse crystals. General chargers are powerless to these coarse crystals, which will gradually reduce the battery capacity and shorten the service life of the battery. Therefore, in addition to charging every day, you should also pay attention to charging as soon as possible after use, and make the battery fully charged as much as possible.
5, regular deep row.
It is also beneficial to "activate" the battery by periodic deep discharge, which can slightly improve the capacity of the battery. The general method is to discharge the battery completely at regular intervals. The method of complete discharge is to ride to the first undervoltage protection under normal load on flat road. Note that we particularly emphasize the first undervoltage protection. After the first undervoltage protection, the battery voltage will rise after a period of time and return to the non-undervoltage state. At this time, if the battery is reused, it will cause great damage to the battery. After fully discharging, fully charge the battery. You will feel that the battery capacity has increased.
6. Develop some good habits of saving electricity.
Use taxiing whenever possible. When going downhill, power off and slow down as early as possible. Enter the taxi in advance when you are about to meet the traffic lights, and try to reduce the brakes. A friend told me that he would rather turn the bay one more time than step on the brakes one less time, which makes sense.
It is best to add riding assistance when starting, which can not only improve the starting speed, but also reduce the power loss and life loss of the battery.
7. Pay attention to the charging environment.
The optimum ambient temperature for charging is 25℃. At present, most chargers have no automatic control system to adapt to the ambient temperature, so most chargers are designed according to the ambient temperature of 25℃, so charging at 25℃ is better. Otherwise, it is inevitable that there will be problems of insufficient charging in winter and excessive charging in summer. However, when the ambient temperature is really lower than 25℃, there will inevitably be problems of overcharging in summer and undercharging in winter. Fortunately, most families now have indoor temperature regulation conditions, so it is best to arrange the battery and charger in a ventilated temperature regulation environment when charging.
In particular, in the northern winter outdoor low temperature state, the battery enters the greenhouse, and the surface will be frosted and dewed. In order to avoid the leakage of the battery caused by frost and dew, the battery should be recharged after the temperature of the battery is raised to close to the indoor temperature and dried.
8, make full use of maintenance conditions
Many dealers of electric bicycles can provide battery overhaul and maintenance services, and we should make full use of these services. Some brands of electric bicycles put forward battery maintenance. For example, regular maintenance of the battery can reduce damage to the battery. Repairing the state of charge of the battery can alleviate the failure of "battery backwardness", which is easy for dealers with maintenance ability. For water loss, it is better to replenish water when battery capacity is 70% than when battery capacity is 40%. Even some brands of products suggest that not repairing the battery within the specified time is equivalent to giving up the warranty period of the battery. Let consumers suffer losses that should not happen. Therefore, consumers should make full use of battery maintenance conditions to extend the service life of batteries.
Through these methods, users can greatly extend the service life of batteries. Some users have short mileage and long battery life, and some problems are relatively difficult to find. Therefore, the "deep discharge" measure mentioned in Article 4 is also an effective way to find the battery problem in time, so it is very difficult not to wait until the battery problem is serious.
A dealer asked: What is the working principle of lead-acid batteries?
A: Lead-acid battery is one of the most widely used batteries. It uses sponge lead as the negative electrode and lead dioxide as the positive electrode. We call these two substances active substances and use sulfuric acid aqueous solution as electrolyte. They participate in the electrochemical reaction of the battery.
The chemical reaction principle of lead-acid battery is as follows
Negative reaction: Pb+HSO4- PbSO4+H++2e
Positive reaction: PbO2+2e+HSO4-+3H+ PbSO4+2H2O.
Electrode reaction: PBO 2+2h+2hso4-+Pb 2pb2so4+2h2o.
Charge state discharge state
From the above reaction principle, it can be seen that when discharging, both anode and cathode materials react with sulfuric acid in electrolyte to generate lead sulfate, so it is called "disulfidation reaction". In general, the generated lead sulfate has loose structure, fine crystal and high electrochemical activity. When this highly active lead sulfate is charged, under the action of current, lead dioxide can be regenerated at the anode and sponge lead can be regenerated at the cathode. Through this stable and reversible process, the battery can store and release electric energy.
Mr. Li asked: What are the causes and hazards of sulfation of lead-acid batteries?
A: Lead sulfate has a high activity for a period of time after its formation. If it is not charged in time or is not fully charged within this period of time, it cannot be converted into positive and negative active substances in time. Lead sulfate recrystallizes at low temperature and precipitates on crystalline lead sulfate. In this way, the crystal particles will continue to increase and become lead sulfate crystals with poor conductivity, which is difficult to dissolve and recover when charging, which is also known as irreversible salinization (this paper). There are many reasons for the failure of the battery, such as fatal electrode grid corrosion, serious deformation of the electrode grid, electrode active material falling off, short circuit or open circuit inside the battery, etc. However, statistics show that most battery failures are caused by irreversible sulfation of electrode active materials. This salt is difficult to recover into lead dioxide and sponge lead when charging, which is very harmful to the battery:
Its formation consumes active substances and reduces the effective capacity of the battery, which will lead to long-term scrapping of the battery; Not only is it difficult to recover itself when charging, but it will also block the gap between porous electrodes, hinder the passage of electrolyte and increase internal resistance; When charging and discharging, more heat will be generated, and the temperature of the battery will increase the corrosion and deformation of the electrode plate, which will make the active material fall off and lead to the scrapping of the battery structure. Reduce the charging efficiency and prolong the charging time, resulting in a waste of time and energy; The phenomenon of electrolytic water is more serious, and the battery is easy to lose water and dry up; Because the capacity is reduced and the output power is insufficient, in order to maintain a certain output, the discharge depth can only be increased, which will make sulfation more serious and form a vicious circle; Due to the consumption of sulfuric acid, the density of electrolyte decreases, the discharge capacity at high current decreases, and the performance decreases.
The main reasons for irreversible sulfation during battery use include:
Frequent deep discharge and overdischarge, without timely charging or insufficient charging; In the state of insufficient power, it is bad not to use the battery for a long time; The performance of batteries in the battery pack is inconsistent, and there are backward batteries with great differences; It shows that the capacity of one battery in the battery pack is obviously lower than that of other batteries, which leads to the voltage drop of the whole battery pack. When charging, the backward battery is overcharged because it is fully charged first and other batteries need to be recharged. When discharging, the backward battery discharges first, which leads to further sulfation, which makes the backwardness more serious and forms a vicious circle. Electrolyte density is too high; Changes of battery ambient temperature.
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-Author: Lao Pan
-Release date: 7:30 am on June 27th, 2004.
Matters needing attention in electric vehicle maintenance
1, Recharge frequently-Lead-acid batteries should keep the habit of charging while using, and can't wait until the battery runs out, which will affect the battery life. If you don't use it for a long time, charge it once a month. Please use a special charger to charge.
2, more maintenance-in case of rain, can not let water flood the hub center; Turn off the switch in time when you get off the bus and inflate the tires at ordinary times; In the case of heavy load such as uphill and headwind, use pedal to assist; If there is any fault, send it to the special maintenance department designated by the manufacturer for maintenance in time.
3. Diligent lubrication —— According to the service conditions, the front axle, rear axle, central axle, flywheel, front fork, rotating fulcrum of shock absorber and other parts should be scrubbed and lubricated once every six months to 1 year (molybdenum disulfide grease is recommended). The transmission parts in the electric hub have been coated with special lubricating oil, so users don't have to scrub and lubricate themselves.
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-Author: Lao Pan
-release date: 2004/11/2707: 31am.
Maintenance of electric vehicles
1. Q: What do you need for routine maintenance of electric vehicles?
A: Proper routine maintenance of electric vehicles can not only facilitate safe riding, but also prolong the life of electric vehicles.
1, before using the electric vehicle, check whether the vehicle is in good condition, such as whether the tire pressure is sufficient, whether the front and rear brakes are sensitive, whether the vehicle has abnormal sound, whether the screws are loose and whether the battery is fully charged.
2. When the vehicle is just starting, it should be accelerated slowly to avoid sudden acceleration and damage to parts. In order to prolong the life of the battery and motor, pedal power is applied when the vehicle starts and climbs.
3. Under the premise of ensuring safety, frequent braking and starting should be reduced as much as possible during driving to save electricity. When braking while driving, loosen the speed control handle to avoid damaging the motor and other components. Turn off the power supply when you get off the bus to prevent the car from starting suddenly when you turn the speed control handle unintentionally and causing an accident.
4. Pay attention when charging. Don't use other brands of chargers. The performance of each brand charger matches the performance of the battery. Only a special charger can achieve the best charging effect.
5. The charger contains high voltage lines. Please do not disassemble it without authorization. When charging, the charger should not be covered with anything, but should be placed in a ventilated place. At the same time, pay attention to prevent liquid and metal particles from entering the charger to prevent them from falling and hitting, so as to avoid damage.
2. Q: How does charging prolong the service life of electric vehicle batteries?
A: At present, most electric bicycles sold in the market use lead-acid batteries without memory effect, and there are different opinions on the best charging method of lead-acid batteries. Now, the technical service department of Lu Qing Company has summarized some experiences in maintaining Panasonic and Haibao batteries in recent years, as well as charging methods and matters needing attention to prolong battery life.
1. Charge frequently to avoid "deep discharge". Ride an electric car to get into the habit of charging on the same day. No matter how far you ride every day, it's best to charge the battery. Don't wait until it's used up.
2. When charging the battery in the car, close the electric door lock, do not charge the battery backwards, and try to charge it once. If you smell strange smell or the battery temperature is too high when charging, you should stop charging immediately and send it to the technical department of Shandong Light Industry Co., Ltd. for maintenance. When removing the battery for charging, do not touch both ends of the electrode with metal such as wet hands or keys to avoid scalding.
3. When it is not used for a long time, charge the battery once a month and store it after it is fully charged. Do not store in the power-off state.
4. Use a special charger when charging. Because the battery formula and technology are different, the technical requirements for chargers are different, and which charger can charge what brand of batteries is different, so don't mix chargers.
In order to protect the battery, users can charge while using it, but they can't use the rising voltage to prevent serious loss of power. When the battery is dead, turn off the power and ride.
6. When charging, don't stop charging immediately when the charging indicator light shows that it is fully charged, and float for another 2-3 hours.
3. Q: Why are high-speed motors noisier than low-speed motors?
A: At present, there are three main types of motors used in electric vehicles: (1) brushed high-speed motors. The motor has high efficiency, strong overload climbing ability and large starting torque, and outputs power after being decelerated by the noisy speed-changing gear device. (2) Brushless low-speed motor. No reduction gear device, with the advantages of maintenance-free and noise-free. But the controller is complex, the starting current is large, and the overload climbing ability is poor. (3) There is a brush low-speed motor and no reduction gear device, which is simple in structure, low in cost, poor in starting uphill overload capacity and high in power consumption.
Because the speed of high-speed motor with brush is relatively high (3000 rpm for high-speed motor and 500 rpm for low-speed motor), it needs to be decelerated by reduction gear device to output large torque power, so its noise is relatively higher than that of low-speed motor. The production technology of high-speed motor is more complicated than that of low-speed motor, and the cost is high, and the price is around 200 yuan. Like some famous brand electric cars, high-speed motors are mostly used. Low-speed motors are often used in miscellaneous cars, low-grade cars and assembly cars to reduce costs. When buying an electric car, don't make a mistake just because the motor is a little bigger. The car price of high-speed motor should be more than 2000 yuan, and the car price of low-speed motor is generally below 2000 yuan. Users should pay more attention when buying a car, not because the motor has no noise and no wear. The main indexes of motor are motor efficiency and power. The biggest weakness of low-speed motor is low efficiency, easy demagnetization of magnetic steel, heavy weight, poor power, weak riding performance and high power consumption. At present, the brands of electric vehicles are particularly miscellaneous, and most of them come from small and medium-sized enterprises. If you want to buy an electric car, please consult carefully and choose carefully.
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-Author: Lao Pan
-Date of issue: 2004/11/2707: 33am
Summary of battery usage of electric vehicles
There are more and more electric vehicle users in Rongcheng, but most users know little about electric vehicle batteries. In fact, as one of the four major components of electric vehicles, batteries have many taboos. At present, electric bicycles are still in the stage of technical development and perfection, and the most important embodiment is the battery. Therefore, the understanding, use and maintenance of batteries need to be cautious.
Improper charging has a serious impact on the battery.
Some people say that "the battery is not broken but charged", which is really true. The charging performance of the battery plays an important role in the service life and performance of the battery, so we must pay attention to the charging method. According to the situation of most users, it is ideal to charge the battery once when the discharge depth is 50%-70%, which can make the battery life reach the best effect. At the same time, the influence of temperature on charging is also considerable. In high temperature season, the battery is overcharged. The battery temperature should be reduced as much as possible to ensure good heat dissipation and prevent charging immediately after exposure to the hot sun. Exposure to the sun will increase the temperature of the battery, increase the activity of various active substances in the battery and affect the service life of the battery. On the contrary, at low temperature, the battery has the problems of poor charging acceptance and insufficient charging. In this case, it is necessary to increase the charging voltage, extend the charging time, and take heat preservation and anti-freezing measures to ensure sufficient electricity and prolong the service life of the battery.
Avoid short circuit and overcharge and discharge.
When the battery is in a short-circuit state, its short-circuit current can reach hundreds of amperes. Light will heat up, and serious will even cause battery explosion. Therefore, when installing or using the battery, you should be especially careful and check that there is no short circuit before putting it into use. At the same time, improper charging is harmful to the battery, but excessive charging and discharging will also seriously damage the battery, which is extremely unfavorable to the electrical performance and cycle life of the battery. Experts say that overcharge will increase the water loss of the battery, accelerate the grid corrosion, soften the active material and increase the probability of battery deformation. Don't put the battery in an overheated environment. And the battery cannot be charged until the temperature of the battery returns to normal. Stop charging when overheating is found, and check the charger and battery.
Proper maintenance can prolong battery life.
Proper maintenance can make the battery life longer and save more investment. It should be noted that the battery should be installed firmly first to prevent the battery from being damaged by vibration when riding. Otherwise, the battery will shake or even fall off and be damaged when the car is driving in bumpy road conditions. Secondly, always check whether the battery connecting wires and loose connectors are firm and whether the wires and connectors are in good contact. Otherwise, it may lead to electric spark and serious battery explosion.
At the same time, always remove the dust and dirt on the battery cover, pay attention to keep the battery dry and clean, and prevent the battery from discharging itself. Be careful not to let the battery discharge when riding. When there is only one indicator light in the battery battery indicator pro, the battery should be charged immediately to avoid excessive discharge. We should also develop the good habit of manually assisting at the beginning and charging the battery every night.
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