Used Car are driven by motors and do not require regular maintenance such as oil, filters, belts, etc. The main task is to perform daily maintenance on the battery pack and motor and keep them clean. This shows that the maintenance of Used Electric Car is indeed less troublesome than traditional vehicles. Quite a few. 1. Air filter replacement There is actually no big difference in the structure of Used Car and fuel vehicles, so components such as air conditioning filters need to be inspected and replaced as appropriate during maintenance just like fuel vehicles. 2. Check the oil level Although Used Car do not have an engine, their batteries and motors also need to be cooled and dissipated by adding coolant. During maintenance, in addition to checking the coolant level, a freezing point test must also be performed, especially when it is about to enter the vehicle. Maintenance before winter. The inspection and replacement of brake fluid and glass fluid should also be paid attention to during maintenance. This is the same for Used Electric Car and fuel vehicles. 3. Power system inspection The inspection process of the power system is similar to that of a fuel vehicle. Only through the power system can we know where it needs to be replaced. However, the inspection of Used Car may be more complicated and requires special inspection of some socket connectors and line insulation protection. 4. Inspection of battery system As an important part of Used Car, batteries are also an important process in maintaining Used Car. Usually there are professional instruments in 4S stores, which can accurately check the status of battery cells.

The Used Car driving in the streets are very eye-catching. Many customers are confused when buying Used Car. They don`t know what to base their judgment on and what characteristics they should choose from. The author below will teach you how to choose an Used Electric Car. Just grab 5 points and start negotiating the price based on these points: 1. Accessible to the car: The main consideration is that the user has limited mobility and can move in a smaller space. 2. Automatic braking: Mainly considering the user's reaction speed and hand and foot coordination, the brake can be braked by releasing the switch. 3. Larger power: Mainly considering the degree of climbing to prevent the car from rolling away at the start. 4. Slow speed: The main consideration is that if the speed is too fast, the user will easily slip off the car when encountering obstacles. 5. Standard voltage: 24V. This is an international practice. Of course, technology updates and whether there will be any changes in the future remains to be verified. For users who don`t know, you must judge whether the Used Electric Car you buy is an authentic product based on the above characteristics. Now some manufacturers use the configuration of electric bicycles to modify them. It is difficult to distinguish from the appearance. You must look at the characteristics of the product. In addition, if the price is low, don`t buy it to avoid being cheated. Try to choose an Used Electric Car manufacturer with its own research and development patents. Only such Used Car can have good performance and guaranteed after-sales service.

Used Car have gradually entered thousands of households and have been well received by everyone. For the majority of users, a common concern is how to effectively extend the life of Used Car. Today we will give you a detailed analysis: 1. When not in use temporarily, charge the battery once every month. Store the battery after it is fully charged. Do not store the battery in a depleted state. 2. Used Car should be cleaned according to normal car washing methods. During the cleaning process, attention should be paid to preventing water from flowing into the charging socket of the vehicle body and preventing short circuits in the vehicle body circuits. 3. Used Car are strictly prohibited from being exposed to the sun. An environment with too high temperature will increase the internal pressure of the battery and cause the battery to lose water, causing the battery activity to decrease and accelerating the aging of the electrode plate. 4. When the vehicle is just started, it should accelerate slowly to prevent sudden sudden acceleration from damaging components. Under the premise of ensuring safety, frequent braking and starting should be minimized while driving to save electric energy. 5. Check the tire pressure frequently. Incorrect tire pressure will cause power consumption, short driving mileage, reduced driving comfort, reduced tire life and reduced driving safety. Check the tire pressure at least once or twice a month. These are the main ways to effectively extend the life of Used Electric Car. You must follow the instructions and perform correct operations. Only in this way can you achieve satisfactory results. More information about Used Car will conti

Many friends choose Used Car to travel as a means of transportation. So are Used Car safe to drive? How long is the range for one charge? This article gives you the answer: Used Car are products designed and produced according to the daily needs of modern friends. The Used Car produced by our factory use high-tech composite materials to make the body. Its advantages include impact resistance, corrosion resistance, toughness, not easy to break, and long life. When designing, the manufacturer does not simply apply the configuration of the original two-wheeled electric bicycle to the Used Used Used Electric Car, but separately configures a motor and controller dedicated to the Used Used Used Electric Car; in terms of functions, it is also different from the two-wheeled electric bicycle. Likewise, you should focus on the convenience and safety of your friends. Maximum speed of Used Car: 40 yards/hour (minimum speed 10 yards/hour, lower speed can be customized if necessary) Charging time: 6-8 hours Charging time: 6-8 hours (extended by about 2 hours in winter), every The trip can reach about 100 kilometers. For this knowledge, first of all, we need to understand that the motor can meet the continuous power requirements of Used Car when driving at the highest load. Continuous power refers to the power output by the motor when it is running stably. In general, the motor speed regulation range of Used Car is It is relatively small, generally between 25% and 100%, mainly to limit the speed and ensure the safety of friends when traveling. In addition, what we also need to know is that at the same time, the Used Used Used Electric Car motor also needs to meet the requirements of the Used Used Used Ele

1. The selection of windproof devices must be appropriate In winter, Used Car windshield quilts are a must-have for many Used Car cyclists. They not only block the wind but also resist the cold. The vendors selling them on the street have made this product a hot seller. But what everyone has not noticed is that the windshield The gloves and knee pads of the wind quilt are integrated. When turning small or sharp turns, they will be restrained and easily fall. Moreover, the width of the windshield quilt exceeds the width of the windshield and is easily scratched by vehicles on both sides. Yes, the best equipment should be to wear a winter coat and a helmet, which can resist impact and protect the top of your head, but you should also pay attention to the operational flexibility during the riding process. 2. Prepare before riding and pay attention while riding Check the front and rear brakes of the Used Car to ensure that the braking is effective, the steering is stable and free, the tire pressure is appropriate, the tire pattern is good, the front and rear wheels rotate flexibly, and the circuit, battery power consumption, lighting effects, speakers, and standard parts all meet the application requirements. . When driving on some bumpy or steeply sloping roads, you should drive at a slow speed or when getting off the car. Turn off the program when executing to avoid inadvertent rotation of the transmission handle and sudden operation of the vehicle. Driving quickly and safely on uneven roads without fully considering the motor, control panel, battery, etc. will reduce the service life and be easily damaged. 3. Cold weather reduces the charge and discharge of rechargeable

1. Production is only allowed after obtaining qualifications Before Used Car were regulated, low-priced Used Car abounded, and since most of the audience were middle- and low-income groups, they attached great importance to price differences. This resulted in some small workshops and small factories without production qualifications. In the market, some no-name, low-price, and inferior Used Car are produced through assembly and shoddy materials and processes. However, there are potential safety risks for consumers to buy such Used Car on the road. Nowadays, with the licensing requirements for Used Car, these Used Car without 3C certification qualifications cannot obtain licenses, which makes consumers not allowed to buy them. In order to solve this problem, the regulatory authorities have raised the qualification threshold and In addition, we will strengthen the investigation and punishment of illegal activities of qualified enterprises producing non-standard products and small workshop enterprises, and strictly investigate and punish unqualified production enterprises. 2. Sales that do not comply with the catalog announcement are prohibited In addition to lacking 3C certification qualifications, according to regulations, Used Car that are not included in the "Announcement of Road Motor Vehicle Manufacturers and Products" and cannot be registered are also prohibited from driving on the road. Therefore, in addition to meeting the production qualifications of a qualified Used Electric Car, in terms of sales, regulatory authorities will also strictly inspect dealers and prohibit the sale of Used Car that are not included in the catalog announcement to

I believe everyone must be familiar with Used Car, because we can often see Used Car on the road now, but they are relatively unfamiliar to some novices. So how do you drive an Used Electric Car? 1. The difference between Used Car and cars lies in their different power systems. Used Car use electric drive as power, and the power system is composed of a battery motor and electronic control, while a traditional car is composed of a fuel engine, transmission, etc. In fact, Used Car also borrow many technologies from cars, and the driving operation is close to the style of a car's automatic transmission, so it is also very convenient to operate. 2. Used Car refer to the use of unconventional vehicle fuels as the power source (or the use of conventional vehicle fuels and new vehicle power devices), integrating vehicle power control and drive technologies, forming technical principles and new features. Technology, new structure of cars. 3. Operation must be carried out in accordance with the operating requirements of the "Used Electric Car Instruction Manual". Overloading and overloading are strictly prohibited. If overloaded regularly, the battery and generator will be damaged and may cause safety issues. The battery cannot be left alone for a long time and should be charged at least once a month. It must be charged and stored, otherwise the battery life will be affected. 4. Although Used Car do not have a gearbox, they still have a gear switch. If we want to start the vehicle, we must first step on the brake pedal to energize the vehicle, then press the start button, then rotate the gear to D and release the handbrake. , release the brake pedal and lightly press the accelerator pedal (to be pre

With the development of society, there are now many Used Car on the road. However, many people actually have many questions about Used Car. For example, are Used Car motor vehicles? Today I will give you a brief introduction. 1. Used Car refer to vehicles that are powered by on-board power and use motors to drive wheels, and comply with the requirements of road traffic and safety regulations. Since it has a smaller impact on the environment than traditional cars, its prospects are widely optimistic, but the current technology is not yet mature. 2. Used Car refer to vehicles that are powered by a fully charged battery and driven by an electric motor. The battery power is supplemented by an external power source and comply with the requirements of road traffic and safety regulations. 3. Since the development of Used Car, there are many types, which are usually classified according to the purpose of the vehicle, the number of on-board power supplies and the composition of the drive system. According to different classifications of uses, Used Car can be divided into three types: Used Car, electric trucks and electric buses. 4. Except for the electric tricycles assembled by ourselves, which do not belong to the category of motor vehicles, the Used Car we buy in various 4S stores that can drive normally on the road, whether pure electric or hybrid, are all motor vehicles as long as they need to be registered. A driver's license is necessary to drive a motor vehicle. This is a necessary condition. 5. Generally speaking, non-motorized vehicles refer to vehicles driven by human power or animal power. For example, the shared bicycles we ride every day are non-motorized vehicles. But gene

After picking up a new car, you must recharge it in time to keep the battery fully charged. In order to avoid damaging the battery, over-discharging, under-charging and over-charging are prohibited during use. Charge it promptly on the day after use, and it shall not exceed 3 days at most. When using an Used Car, it is forbidden to slam on the accelerator (throttle) and the speed should be increased slowly, otherwise it will seriously affect the battery life or even burn out the motor. In daily use, Used Electric Car should try not to travel to the maximum mileage. The optimal mileage is 1/3--2/3 of the longest mileage. (For example, for a car with a maximum driving range of 150km, it is best not to exceed 100km in daily use. This can greatly extend the service life of the battery and reduce the cost of battery use.) When an Used Car is not in use, the battery needs to be fully charged and stored, and recharged once a month to avoid long-term power loss leading to sulfation of the battery plates. The charger used with the vehicle must have sufficient accuracy and stable voltage and current performance and pass the company's technical testing and certification. It is strictly prohibited to use chargers with poor quality, low price and poor aging resistance, otherwise the battery will be damaged. The battery shall not be placed in a sealed container, shall not be near an open flame, shall not be thrown into a fire or immersed in water, and shall not be exposed directly to the sun. Gel batteries are acidic solutions. If they come into contact with skin or clothing, they must be rinsed with clean water immediately. The ambient tem

The Used Car driving in the streets are very eye-catching. Many customers are confused when buying Used Car. They don`t know what to base their judgment on and what characteristics they should choose from. The author below will teach you how to choose an Used Electric Car. Just grab 5 points and start negotiating the price based on these points: 1. Accessible to the car: The main consideration is that the user has limited mobility and can move in a smaller space. 2. Automatic braking: Mainly considering the user's reaction speed and hand and foot coordination, the brake can be braked by releasing the switch. 3. Larger power: Mainly considering the degree of climbing to prevent the car from rolling away at the start. 4. Slow speed: The main consideration is that if the speed is too fast, the user will easily slip off the car when encountering obstacles. 5. Standard voltage: 24V. This is an international practice. Of course, technology updates and whether there will be any changes in the future remains to be verified. For users who don`t know, you must judge whether the Used Electric Car you buy is an authentic product based on the above characteristics. Now some manufacturers use the configuration of electric bicycles to modify them. It is difficult to distinguish from the appearance. You must look at the characteristics of the product. In addition, if the price is low, don`t buy it to avoid being cheated. Try to choose an Used Electric Car manufacturer with its own research and development patents. Only such Used Car can have good performance and guaranteed after-sales service.

Charging and driving of Used Car. Used Car have become a popular travel trend. What issues should we pay attention to when charging and driving Used Car? Let`s analyze it together, mainly reflected in the following five points: 1. Before using an Used Electric Car, you should pay attention to 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 there are any abnormal noises in the vehicle, whether the screws are loose, whether the battery is fully charged, etc. 2. The charger contains a high-voltage circuit. Do not disassemble it without authorization. When charging, the charger should not be covered with anything and should be placed in a ventilated place. At the same time, prevent liquid and metal particles from entering the charger, and prevent falling and impact, which may cause damage. Also take the key out. 3. Pay attention when charging. Do not use other brands of chargers when charging Used Car. The performance of each brand of charger matches the battery. Only a dedicated charger can achieve the best results. 4. When an Used Electric Car is just started, it should be accelerated slowly to avoid damage to vital parts due to sudden acceleration. 5. Under the premise of ensuring safety, frequent braking and starting of Used Car should be minimized while driving to save electric energy.

Speaking of the power problem of Used Car, in fact, the simplest way to understand it is to improve the overall performance by increasing the wattage of the generator of the car itself and increasing the capacity of the battery. Under normal circumstances, 2200W motors are basically used in plain areas. You can drive normally. But in some places, such as Sichuan and other mountainous areas, where there are many slopes and steep slopes, power is increased by increasing the power of the motor. Basically, mountainous areas use 3500-watt AC motors or 4000-watt AC motors. , only in this way can the power be more powerful on mountain roads and slopes. Otherwise, it will be very difficult to climb hills, and if a smaller motor is used, it will cause consequential damage to the controller and other components. Nowadays, Used Electric Car basically use x8 fiberglass models, which have very good resistance to impact. Moreover, the braking system has been enhanced to a four-wheel braking system, with front disc brakes and rear drum brakes, which is also very good in terms of safety. protection. Compared with traditional four-wheel Used Car, Used Car reduce exhaust emissions and greatly reduce greenhouse gas emissions, which has very good advantages for products. Therefore, the cleaning of Used Car is also particular. It is best to use special cleaning agents for cleaning. Do not use organic solvents such as thinner, gasoline or windshield washer for cleaning. The main dirt on the ceiling of Used Electric Car is floating ash. If these floating ash are not removed in time, they will adhere to the ceiling under the action of water vapor in the air, making the ceiling feel gray. Freque

As the Used Electric Car industry develops more and more, customer demand is getting higher and higher, especially the lightweight of vehicles and the increase in driving range, and the demand for lithium batteries for Used Car is increasing. So let`s analyze the safety of lithium batteries for Used Car as follows: As long as it is an Used Electric Car lithium battery, there is a risk of explosion, but the probability of this risk is very small. But once it explodes, the larger the capacity of the lithium battery for Used Car, the more powerful the explosion will be. An important reason for the safety of lithium batteries is battery short circuit. Whether it is battery short circuit or overcharging, it will cause a large amount of heat and gas to accumulate inside the Used Electric Car lithium battery in a short period of time. In order to release the pressure, the lithium battery will either excite the internal If the pressure release device is used, excessive pressure will directly cause the shell to crack. Both cases will cause the internal materials of the Used Electric Car battery to directly contact the air, causing combustion and, in severe cases, explosion. The above are the reasons for the explosion of lithium batteries. Let's look at the maintenance of lead-acid batteries. The reason why they will not explode is that there are vents on the battery case. If the pressure reaches a certain level during charging and discharging, it will automatically release it. This is The reason why lead-acid batteries will not explode is that even if they explode, they will not produce a large amount of open flames, and the probability is much smaller than that of lithium batteries. Therefore

(1) High vehicle efficiency of Used Car. The vehicle efficiency of Used Electric Car is much higher than that of fuel vehicles. The actual efficiency of ordinary fuel vehicles (Tank to Wheel) is only 16%, and the vehicle efficiency reaches 30% after adopting hybrid power. The vehicle efficiency and FCV (fuel cell vehicle) of Used Electric Car are 81% and 50% respectively. Used Electric Car replace the energy conversion method of "chemical energy-thermal energy-mechanical energy" with "chemical energy-electrical energy-mechanical energy". The conversion efficiency of "electrical energy" as the medium will be as high as 90%, while the conversion method of "thermal energy" as the medium The highest is 40%. The overall efficiency of Used Car is also higher than that of ordinary fuel vehicles, and improvements in fuel preparation efficiency will further widen the gap with fuel vehicles. The overall efficiency of Used Electric Car is 15% and 14% higher than that of ordinary fuel vehicles respectively. The current efficiency of using fossil fuels to produce electricity and hydrogen is low. However, as the application efficiency of nuclear power, green energy, and hydrogen production technology further improve, the overall efficiency of Used Car is expected to be further improved. The electrification of automobiles makes vehicles more efficient, brings high energy utilization, and reduces the "money bags" of the common people. As for the high-level arguments such as air pollution, energy crisis, carbon dioxide emissions, etc., they are nothing more than issues of comprehensive energy utilization rate. (2) The structure is simple, and Used Car will reduce parts by 1/3. The number of parts for an ordinary fuel vehi

With the increase in national income, China's tourism industry has developed rapidly. According to data released by the National Tourism Administration Statistics Center, China's domestic tourist arrivals exceeded 4 billion last year and 120 million outbound tourists. Ranked first in the world. Under such strong market demand, Used Car have become the preferred means of transportation for many tourists due to their advantages such as being light, comfortable and close to nature. Compared with traditional buses, Used Car are comfortable and ventilated, and tourists will not feel the discomfort of motion sickness. , and you can also enjoy the beautiful scenery along the way, so many tourists prefer to take Used Car. For scenic spots, Used Car are small in size, can carry a large number of passengers, are energy-saving, lightweight, easy to maintain, and have better customer experience than buses. Therefore, more and more scenic spots have begun to introduce Used Car in large quantities to increase competition among scenic spots. force. 1. Car model When I usually meet with many customers, they will ask how much an Used Electric Car costs when consulting. But in many cases, the prices are different for different models. For example, factors such as passenger capacity, appearance, and whether it is closed or not will affect the price of a car. price. 2. Configuration The internal configuration of an Used Electric Car such as batteries, tires, and motors directly affects a vehicle's performance, service life, cruising range and other key factors. Therefore, the configuration of an Used Electric Car directly affects the price. Many lay customers only look at the pr

Nowadays, Used Car are becoming more and more popular in tourist areas, but what follows is that we need to have a lot of emergency methods and prevention methods. For example, many Used Electric Car drivers may encounter the embarrassing situation of the Used Electric Car running out of power midway. Not only It will affect the order of the tourist area and leave a bad experience for tourists. Do you know how to prevent this from happening? Today I will share several ways to save power in Used Car to relieve everyone`s dilemma. 1. Avoid sudden stops of Used Car while driving. Sudden braking should be avoided as much as possible, because sudden braking will not only accelerate the grinding of the brake linings, but also the current caused by emergency braking will have an impact on the motor controller, affecting the driving range and the life of the motor controller. 2. Maintain normal tire pressure of Used Car. Insufficient tire pressure will increase rolling resistance and increase power consumption, so normal tire pressure should be maintained. 3. Be careful to avoid rapid acceleration of Used Car. If we accelerate and start quickly, the current in the high-voltage circuit will be very large and consume electricity. Frequent acceleration and start will affect the life of the motor controller and power battery, and shorten the driving range. 4. Used Car should try to maintain a constant speed. Vehicles should maintain a stable driving speed as road and traffic conditions permit. When the vehicle starts, after accelerating to a certain speed, you can relax the accelerator pedal appropriately and maintain the current speed.

After using an Used Used Car for a period of time, the car body will become dusty and dirty. Many car owners need to clean and maintain their cars at this time, but they are very particular when cleaning their cars, whether you do it yourself Whether you are cleaning or going to a car wash to wash your car, you must understand the requirements for car washing. All models of Used Car are independently designed and have independent intellectual property rights. The company can tailor-make deformed vehicles, special vehicles, modified vehicles, etc. according to customer needs, striving to meet customer needs. Used Car should be cleaned according to normal car washing methods. The following matters need to be paid attention to during the cleaning process: 1. If the patrol car is sent to the automatic cleaning equipment for cleaning, there is no need to remove the antenna if the car is equipped with a roof antenna. 2. During the cleaning process of Used Car, attention should be paid to preventing water from flowing into the charging socket of the vehicle body and preventing short circuits in the vehicle body circuits. If water flows in, please do not start the vehicle immediately and contact the relevant technical personnel immediately. 3. The longer salt, dust, insects, bird droppings and other debris stick to the car, the more damaging it will be to the car, so they should be cleaned in time. 4. When cleaning the paint surface of the Used Used Car body, do not use brushes or coarse cloth to avoid leaving scratch marks. Special cleaning tools should be used. 5. When cleaning the power battery part, you must clean it more carefully. Do not use a water gun to clean i

As a series of new Used Electric Car that appear in the market and are suitable for special places, Used Electric Car provide greater convenience for our daily lives. Because it is an electric special vehicle, there are many kinds of faults and varied phenomena during use. Fault judgment skills are the key to quickly and accurately repairing the vehicle. The so-called fault judgment skills are a set of logical ideas for finding faults and the order of inspection methods formed in the mind of the maintenance person based on the fault phenomenon. 1. Clean first and then test As for Used Electric Car, many circuit faults are caused by the working environment, such as dust on the charger controller circuit board and various soft faults caused by dirty adjustable potentiometers. Accordingly, when checking for faults, you should first clean the inside of the machine and eliminate the fault caused by contamination before proceeding to check. 2. Go outside the machine first, then inside the machine Specific internal faults of Used Electric Car are all external manifestations. Different external manifestations reflect corresponding internal device faults. When diagnosing and inspecting faults, start from outside the machine and gradually go deep inside. This can not only avoid blindness, reduce unnecessary losses, but also greatly improve maintenance. s efficiency. 3. Power supply first and then load Faults in the power supply part of Used Electric Car account for a large proportion in maintenance. The power supply system is the center of energy supply for the whole machine. The power supply supplies electric energy and the load pump electric energy, and relies on elect

Used Electric Car now occupy a large market share. Many people use Used Electric Car in their daily lives, and Used Car charging stations have also developed accordingly. Used Car charging stations are very popular on the market now. They can facilitate the charging of Used Electric Car, improve the problem of difficulty in charging Used Electric Car, and have very good market development prospects. I believe that to a certain extent, we should actively support this move by large energy companies. This initiative will contribute to the technological research and development progress, scale and commercialization process of my country's Used Electric Car. The inconvenience caused by the lack of Used Car charging stations will reduce people's interest in using Used Electric Car, and the reduction in the actual operation of Used Electric Car will in turn slow down technological progress and large-scale development, thereby reducing the demand for charging stations, which actually It is a contraction-type reverse cycle. With the rapid development of my country's economy, transportation has also been greatly improved. As a new type of transportation developed in recent years, Used Electric Car have advantages that many other transportation methods do not have, such as being lightweight, environmentally friendly, and economical. Safe and environmentally friendly Used Electric Car have replaced motorcycles. As China's urban traffic pressure and environmental protection pressure have reached its extreme, it has become a national industry direction that cannot be argued about. At the same time, as China's urban and rural road construction and road conditions improve, It is also an irreversible market de

With the advancement of science and technology, the battery industry continues to develop, providing conditions for the popularization of Used Car. Used Car are a popular transportation tool for many elderly people. They are very simple to operate, easy to use, slow, energy-saving and environmentally friendly. However, improper charging of Used Electric Car can easily lead to serious consequences. Improper charging can cause the capacity of Used Car to decrease. Self-discharge The phenomenon of a fully charged battery gradually losing power when left unused is called self-discharge. Self-discharge is inevitable. Under normal circumstances, the daily discharge rate should not exceed the standard in the instruction manual. The active material on the plate falls off. During normal use and charging of the electric sightseeing car battery, the volume of the active material on the plate continues to expand and contract, which will cause the active material to slowly fall off. If used improperly, the active material will fall off quickly and in large quantities, causing a short circuit on the plate. The main reason for the active material of the plate to fall off is that the current is too large or the temperature is too high during charging. Frequent overcharging, etc. During discharge, excessive current will cause the active material to fall off. Cracks in the casing or cracks in the sealing glue will cause the electrolyte to leak out, causing the liquid level to drop. If there are slight cracks in the internal wall, the two single-cell batteries will be connected, causing the voltage to drop. Blockage of the vent holes will prevent gas from being released, causing excessive pressure in