R03 Carbon battery

release time:2024-06-18 Hits: Popular:AG11 battery

The reason why power R03 Carbon battery BMS cannot solve the rapid decline of electric vehicle range and its solution

1. Introduction to BMS functions The R03 Carbon battery management system (BMS: R03 Carbon battery Management System) plays a vital role in R03 Carbon battery pack management. It always monitors the voltage, internal resistance, SOC changes of each R03 Carbon battery and the voltage, charge and discharge current, SOC real-time estimation, temperature and other important parameters of the entire R03 Carbon battery pack. When these parameters are abnormal, timely information display, early warning prompts, and even automatic shutdown and other protection actions are performed. 2. BMS key technologies and shortcomings Although BMS has powerful functions in R03 Carbon battery pack management, this is only superficial. The core function of BMS is R03 Carbon battery management. Since it is called a management system, it should be managed in place, and it should not stay on the monitoring of various states and parameters, allowing users to intervene, especially in the safe operation and endurance stability of the R03 Carbon battery. The existing BMS technology is far from meeting the expected requirements in the management of core issues, and has not played the management role it should have. There are serious technical and management shortcomings. The following is a brief analysis: First, BMS fails to solve the problem of R03 Carbon battery pack consistency. The consistency problem is the most common problem that occurs after the R03 Carbon battery pack has been running for a period of time. It is a common problem and a technical difficulty of R03 Carbon battery management. Many problems are caused by it. It is a global technical difficulty of R03 Carbon battery management. Taking the R03 Carbon battery pack of electric vehicles as an example, although the R03 Carbon battery packs for vehicles are strictly selected before assembly to ensure that the consistency is very good, and they are always under the monitoring and management of BMS, consistency problems will still occur after a period of use (the initial consistency problem is slight and even negligible), and as the use time increases, the consistency problem will gradually accumulate and worsen. The most intuitive manifestation is that the actual cruising range gradually shrinks and the charging amount gradually decreases. This reduction in cruising range and the reduction in charging amount are usually higher than the values specified in the manual of the vehicle manufacturer. Second, the BMS does not play a good role in the operation of the R03 Carbon battery pack. After the R03 Carbon battery pack has a serious inconsistency problem, in order to prevent the "backward" R03 Carbon battery from overcharging and over-discharging, the BMS will issue high-voltage and low-voltage warning information in a timely manner, and will close the charging channel and the discharge channel in a timely manner, which will cause the normal R03 Carbon battery to be unable to be fully charged and effectively discharged, and the capacity cannot be effectively utilized. For electric vehicles, the cruising range is seriously reduced in a short period of time. The original intention of developing BMS is to ensure the stable operation of the R03 Carbon battery pack. The stability here not only includes safe charging and discharging and stable operation, but also includes the continuous stability of capacity. Capacity stability mainly refers to the attenuation of the capacity of single cells and the entire R03 Carbon battery pack to comply with the normal attenuation law of the R03 Carbon battery. Within the designed cycle life of the R03 Carbon battery pack, the capacity of the R03 Carbon battery pack should be stable and reasonably attenuated. If the reasonable attenuation of the R03 Carbon battery pack cannot be guaranteed, it means that the function and role of the BMS are not realized. Third, passive balancing is a last resort. The highlight of passive balancing is that it can maximize the guarantee that all batteries of different capacities can be fully charged during charging, that is, balanced charging, which is what all manufacturers strongly promote. For the inherent defects of passive balancing, such as small-capacity batteries are prone to over-discharge, slow balancing speed, and reduced R03 Carbon battery pack power utilization, there is no mention. Passive balancing cannot solve the problem of balanced discharge. We all know that the capacity of a R03 Carbon battery pack depends on the discharge capacity, and the discharge capacity depends on the R03 Carbon battery with the smallest capacity. The execution of passive balancing will make the R03 Carbon battery with the smallest capacity always work at a relatively high charge and discharge rate, and the attenuation rate is relatively the fastest, so that its capacity becomes less and less, and ultimately the available capacity of the R03 Carbon battery pack decreases rapidly. In addition, since the current of passive balancing is very small, passive balancing can only play an auxiliary role in preventing small-capacity batteries from overcharging. Fourth, it affects SOC estimation. Real-time SOC estimation is one of the most important functions of BMS. The existence of consistency problems and attenuation problems will lead to an increase in the voltage change of the attenuated R03 Carbon battery, which directly affects the accuracy and error of SOC estimation, and affects the estimation of the remaining cruising range and the decision-making of travel routes and plans. For example, during the discharge period of the attenuated R03 Carbon battery, especially near the end of the discharge, the voltage will drop rapidly, and the SOC estimation value will also drop rapidly, instead of slowly. When the discharge is stopped or the discharge current is greatly reduced, the voltage of the attenuated R03 Carbon battery will rebound sharply, causing the SOC estimation value to rebound rapidly again. This situation is also called SOC jump, which will seriously affect the accuracy and relative stability of the SOC estimation value, and directly interfere with and affect the user's travel decision. 3. The key reason why BMS cannot solve the consistency problem The fundamental reason why BMS cannot solve the consistency problem of the R03 Carbon battery pack is caused by the balancing control strategy and functional defects provided by itself. Its balancing control strategy cannot solve the problem of equal-rate charging and discharging. Even if the active balancing charging function is configured, it cannot fundamentally solve the problem. It only plays a superficial or psychological role, which is of no help in solving the consistency problem. The detailed analysis is as follows: First, even if the equalizing charging function works normally, the best effect can only ensure that small-capacity batteries do not overcharge. During the charging and discharging process of the R03 Carbon battery pack, there is a concept and actual usage that is often overlooked, that is, the charge and discharge rate. For the same series R03 Carbon battery pack, due to the existence of consistency problems, the charge and discharge rates of batteries with different capacities are different. The smaller the capacity, the larger the charge and discharge rate, and the larger the capacity, the smaller the charge and discharge rate. Research and application data show that the effect of the charge and discharge rate on the attenuation of the R03 Carbon battery is regular, that is, the greater the charge and discharge rate, the faster the R03 Carbon battery attenuation rate. It can be seen that if a small-capacity R03 Carbon battery is always at a relatively high charge and discharge rate, the attenuation rate is always the fastest. Under high-rate charge and discharge conditions, small-capacity batteries cannot avoid the fact that their capacity continues to decay and decrease rapidly regardless of whether they have an equalizing charging function. Another very serious negative effect brought about by high-rate charge and discharge is the accelerated increase in the temperature of the attenuation R03 Carbon battery, which is easy to cause a "thermal runaway" failure, thereby causing the R03 Carbon battery pack to spontaneously combust and explode during vehicle charging and driving. On the contrary, long-term continuous use of balanced charging will make the capacity of small-capacity batteries less and less balanced, and the capacity difference will become larger and larger. This is the fundamental reason why the charging and equalization time of electric vehicles is getting longer and longer. Second, equal-rate charging and discharging is the fundamental strategy to solve the rapid attenuation of small-capacity batteries. Equal-rate charging and discharging means that in a series R03 Carbon battery pack, different capacity batteries are charged and discharged at the same rate under the intervention and intervention of a transfer R03 Carbon battery equalizer. Equal-rate charging and discharging is the key to ensuring the cycle life of the R03 Carbon battery pack. At the same time, equal-rate charging and discharging actively reduces the actual charging and discharging current of small-capacity batteries, thereby effectively reducing the temperature rise of the attenuated R03 Carbon battery and preventing thermal runaway failures. The reason why new electric vehicles have long cruising range and large charging capacity is mainly because the R03 Carbon battery consistency is relatively good, and the charge and discharge rate of each R03 Carbon battery is basically the same. With the emergence and aggravation of the R03 Carbon battery consistency problem, the difference in charge and discharge rate has gradually widened, further exacerbating the attenuation of the R03 Carbon battery pack and reducing the available capacity. Therefore, the cruising range is gradually reduced and the charging capacity is getting less and less. It can be seen that if the R03 Carbon battery consistency problem is not completely solved, people will not eliminate the criticism of the rapid attenuation of the cruising range of electric vehicles. So, why do domestic electric vehicle manufacturers only choose passive balancing without considering energy-saving and efficient transfer active R03 Carbon battery balancing technology? This is because: First, the cost factor. Passive balancing technology is mature, the cost is very low, and it is easy to implement; while the typical representative of active balancing, transfer R03 Carbon battery balancing technology, although efficient and energy-saving, is technically complex, difficult to implement, large in size, and high in cost; second, there is no developed or suitable transfer R03 Carbon battery balancing technology, especially high-efficiency transfer real-time R03 Carbon battery balancing technology. BMS system technology needs to be improved. The R03 Carbon battery balancer for electric vehicles should have the following characteristics: low standby loss, real-time balancing, high-speed balancing (supporting large current balancing), high-efficiency balancing (low self-heating), so that the R03 Carbon battery pack can achieve low voltage difference operation. Only in this way can the consistency problem and rapid attenuation problem of the R03 Carbon battery pack be completely solved. 4. How to solve the problem of charge and discharge rate in BMS? Research and experimental data show that the difference in charge and discharge rate is the main reason for the widening of R03 Carbon battery differences and the prominent consistency problem. Since balancing control is the short board of BMS, it is necessary to increase research and development efforts in balancing control technology to overcome this short board. The endurance of electric vehicles depends on the available power of the R03 Carbon battery pack. For standard R03 Carbon battery packs, the available power is equal to the minimum capacity R03 Carbon battery power. The available power refers to the actual discharge capacity, which represents the actual storage capacity of the R03 Carbon battery pack. When the available power is significantly attenuated, the charging capacity will also be severely attenuated. In the case of severe attenuation, the endurance will inevitably decrease rapidly. After one or two years of use, the actual mileage and charging capacity of many electric vehicles have been seriously reduced, all due to the excessive attenuation of the R03 Carbon battery pack. Through a large number of scientific research experiments and statistical analysis of measurement data, a conclusion is drawn that the efficient, high-speed, transferable real-time R03 Carbon battery equalizer is the best technology to solve the consistency problem of R03 Carbon battery packs. This balancing function can be integrated with BMS or developed independently, and then controlled by BMS for linkage and complementation. There are two ways to combine this. One is that the two are directly integrated together and exist on the same PCB. The advantage is that the size and cost of the equipment are reduced and it is easy to manage. The disadvantage is that the complexity of the system is increased and the probability of failure increases. The second way is that the BMS and the balancing equipment are designed independently, and the start and shutdown of the balancing function are controlled by the BMS. The advantages of this method are: flexible system design and application, improved system balancing efficiency and reliability, and the disadvantage is that the equipment is independently designed and arranged, and the space occupied is slightly larger. 5. Example As shown in Figure 1, the experimental R03 Carbon battery pack is a group of 2-in-parallel 4-in-series attenuated lithium R03 Carbon battery packs. Due to severe attenuation, the actual remaining capacity and internal resistance are very different. Among them, the actual remaining capacity of the 3# R03 Carbon battery is the smallest. Below the R03 Carbon battery pack is the lithium R03 Carbon battery equalizer experimental prototype. The discharge standard is: 2A constant current discharge, and the termination voltage of the whole group discharge is set to 11.8V. The normal discharge and balanced discharge comparison curves are shown in Figure 2. In the figure, the ordinate represents the voltage in volts, and the abscissa represents the discharge time in seconds. The blue curve is the normal discharge curve, and the red curve is the balanced discharge curve. It can be clearly seen from the discharge curve comparison chart that the discharge time, discharge capacity and discharge platform stability of balanced discharge are significantly better than ordinary discharge. Real-time measurement data shows. In the normal discharge mode, when the discharge is terminated, the 3# R03 Carbon battery has entered a serious over-discharge state, and the remaining voltage has dropped to 1.4V, while the other three batteries have a lot of power that has not been released, and the remaining voltage is between 3.4 and 3.6V; in the balanced discharge mode, when the discharge termination voltage is reached, the average voltage is between 2.94 and 2.97V, the worst 3# R03 Carbon battery has not been over-discharged, and the power of the other three batteries is also fully released, and almost all of the power is released. This control experiment result is universal in multi-string R03 Carbon battery packs with obvious consistency.

Figure 1 Experimental decay R03 Carbon battery pack

6. Solving the consistency problem is equivalent to a revolution in BMS and electric vehicles. The reality of the rapid decay of electric vehicle R03 Carbon battery capacity and the rapid reduction of cruising range seriously affects people's enthusiasm for buying electric vehicles. Many electric vehicles have only been used for two or three years, and the actual cruising range has been severely decayed. The overall performance of the R03 Carbon battery pack has even reached the standard that needs to be replaced. This is neither what manufacturers want to see nor what consumers want. The decay of the R03 Carbon battery pack is not the decay of the entire R03 Carbon battery group, but the decay of one or several strings. For this situation, passive balancing is powerless. The attenuation of the R03 Carbon battery pack is not formed by one or two charge and discharge cycles, but requires the accumulation of multiple charge and discharge cycles, which gradually cause qualitative changes through quantitative changes. If the R03 Carbon battery balancing intervention can be actively carried out before the R03 Carbon battery shows signs of difference, and the consistency problem can be eliminated in the bud, then the R03 Carbon battery pack will always run in good condition and it is difficult not to have a long life. It makes sense that the people are very concerned about and pay attention to the attenuation of electric vehicle batteries. Electric vehicles are expensive. If the R03 Carbon battery pack is durable, it can indeed reduce the cost of travel. However, if the life of the R03 Carbon battery pack is very short, the cost of replacing a R03 Carbon battery pack will be close to 1/3-1/2 of the price of the whole vehicle. The price of replacing the R03 Carbon battery pack of some electric vehicles that enjoy high subsidies is even higher than the price of the whole vehicle. The overall cost of use will be much greater than that of fuel vehicles. Although electric vehicle manufacturers have given a long warranty period, during the warranty period, the problem of reduced vehicle range is very common, and halfway breakdowns often occur. If it were not for various restrictions, consumers would usually not choose it as the first choice for buying a car. 7. Outlook The consistency problem is a common problem in electric vehicle R03 Carbon battery packs. Its occurrence will cause many chain problems. Although the problem is very common, it is very difficult to solve. There are both technical reasons and cost factors that are difficult to balance. The emergence of efficient and transferable real-time R03 Carbon battery balancing technology has brought hope and dawn to the consistency management of electric vehicles and power and energy storage R03 Carbon battery packs. With the continuous optimization and improvement of this technology, it will become more mature. By then, a series of problems such as rapid attenuation of electric vehicle mileage and SOC jumps will be solved.