Digital battery

1 Introduction

 

The supply current lithium Sony VGP-BPS2B Sony VGP-BPS2C battery supply system development the main question is: After the battery in a group of security and life has decreased significantly, and even the fire of the battery frequent explosions and other serious accidents. The main reason contributing to this problem lies in battery technology Lithium Power Group, the study group applied technology and equipment, delays in development, to secure the integration of power lithium battery system to provide users of technology of lithium batteries integration of systems and products to solve the current problem and to promote the development of the power of lithium important subject.

 

Currently, the only battery power lithium has been basically have the extension and application conditions, but the technology of existing group, the group applied technology and equipment levels are not yet ripe. In other words, only lithium battery basically resolved the issues of security and life, and promotes the development of the power of lithium, the key is the cell technology, the technology group and BMS. Inspiron 6000 battery Inspiron 9300 battery

 

Determine the quality of individual cells in a group of post-quality battery power. In applications of battery power, the consistency of single-cell performance is particularly important given the current level of process control single manufacturing cell, through the battery produced in accordance with its actual performance filter, group, assembly is a realistic way. Currently, implementation of screening in industrial production, gathering method is based on the battery post in a small number of static parameters, with the group on drums, with the set control standard determines the distribution group completed the battery when the battery status of the single line of each sex. In the battery pack in use, the group differences in each state of the single battery battery appear gradually. Battery Management System (BMS) battery using process management, battery status in every single cell to adapt to a certain extent, you can keep the battery status in each cell of the unique coherence in order to avoid differences in the state cells caused by the accelerated deterioration of battery performance. The development needs of lithium batteries to raise the level of control of production process, the Panel selection of drums and distribution methods and systems for effective KD476 TD347 battery management and promote jointly.

 

2 lithium batteries power the concept of security and life

 

2.1 The root causes of insecurity in the battery

 

When the battery is part of the deviation occurs, as when the internal short circuit, discharge, high current overload, it will generate much heat, causing the battery to the system increases the temperature. When the battery system and achieve a higher temperature, resulting in a series of side effects, so the battery produces heat damage due to battery electrolyte flammable liquid, so the worst case, the battery would catch fire [1].

 

In the case of non-normal use (such as overhead), lithium battery anode ion is likely to surface, the electron precipitation as lithium metal, and gradually assembled in a lithium dendrite perforated diaphragm, Connectivity is negative, causing the battery internal micro-short. Lithium-ion batteries used in high compression, high-boiling point organic electrolyte. In the short-circuit, overload, high temperature and not the other-the conditions of normal use, the lithium-ion battery internal temperature increases, the electrolyte may be decomposed into a number of gas will be generated within the waterproof case for relatively high pressure. Once this pressure great enough to break the casing of the battery, rupture occurs, and even lead to combustion or explosion [2]. A1175 MacBook Pro 15 inch battery

 

High power load and discharge the large capacity lithium-powered batteries in the harsh conditions of use of part of the battery easier to induce deviations occur, giving rise to questions security.

 

2.2 Battery Management System (BMS) the important role of

 

Battery Li-ion power ideal for high performance, consistency, as long as the use of the filling process, however, well placed, there is no security problem, but the reality is that the plant quality mobile phone battery in full conformity with the standards, but should use an incident of explosion, Pack laptop battery is also continuing fire, explosions, and product recalls reported. Of life resulting from the battery until the end of recovery, there are security issues, even at the plant in full compliance with international safety standards in the course of evolution of the state of Security in a state of insecurity and of good quality, single cell performance to reach the lifetime limit of gradual decline, poor quality of the single cell, as part of its performance will start to appear and a variety of abnormal deterioration recession, worried about the insecurity of the state to enter. It is a gradual process of incremental changes. The battery management system is that unlike some battery manufacturers as a luxury but a must have, but also applied consistently throughout the battery. Applications of the battery management system at home and abroad have been many studies and start in many areas have been able to meet the needs of specific markets, applications, power lithium battery for the system of advanced battery management requirements more stringent to ensure the safe use of battery power, battery power lithium-management system the primary task. Satellite A80 battery Satellite M100 battery

 

3 Battery Management Systems

 

A typical battery charge balance system management, its methods of work is to connect a battery good set of charges at the same time, each battery of simple tests in the battery voltage terminal when a single voltage battery terminal is high, individual cells in parallel with the balance of the circuit for the diversion battery, reduce speed single battery charge and the rate of terminal voltage increases, so that the only voltage battery terminal tends to a balanced line, thereby to avoid the standard battery charge of each single battery and discharge characteristics differences affect battery life. As the shunt charging the battery in parallel with the monomer part of the pricing of energy consumption of a balanced circuit, fever balanced circuit, a balanced circuit balanced the limited capacity. For high capacity, high power, high current load, the remaining balance of the capacity of the circuit can respond to real needs.

 

In the last part of the life of the battery, battery performance, the gradual internal deterioration, under the old ceiling value of rejection and constant current charge-discharge or recharge values occur in May excessive discharge, more responsible, leading to a further deterioration of the battery internal resistance and other parameters, charge and discharge process of the battery will be seriously hot, the existing BMS, but it can monitor the battery temperature increases heat anomaly of the external load or discharge path, but this time the battery is already in a state of insecurity, to cut the access road can not prevent the cell from the electrochemical reaction process except the battery continues to warm, and even a risk of explosion still exists. Anomalies of temperature increases in the farm, suddenly cut the path of discharge for the equipment require continuous power supply, such as electric vehicles, in May, the device to perform the security issues. Tecra A4 battery Tecra A5 battery

 

4 based on measuring the internal resistance and state of the battery system management more

 

Studies have shown that with the battery charge - discharge cycles increases, reduced battery capacity, increases the internal resistance of the battery, the battery performance degradation and eventually internal failure complete process is a gradual and cumulative, inconsistencies in the group will accelerate the battery in the battery state of insecurity.

 

This paper presents a comparison of the measurement of internal resistance and the management system of the state of the battery, as shown in Figure 1, to control the heart of microcontroller, pre-stored in the memory of every single voltage battery terminal under different resistance values of the initial value and the error allowed the charging process of each single cell in different sections of the voltage rate of rise of tension terminal and the error allow the value of the cumulative value of the load, the load voltage, the discharge voltage range, charging cut-off voltage, the discharge cut-off voltage, battery temperature, the range load current value and perception of current error to allow the value of discharge current to protect the value of a balanced starting voltage, the value of parameters such as voltage unbalance. Charging and discharging process of loading and unloading process of testing various parameters of each charging process before the process of billing and charging after the battery to measure and record every single potential terminal battery terminal voltage rising rate the load current, load volume and internal resistance of the battery, and with measured and recorded before the charging parameters to compare, analyze the amount of battery charge and battery only internal resistance, the voltage of terminal voltage terminals to increase the rate of volume change to determine the battery internal process performance and the extent of deterioration to the failure of the battery and can be an early warning of security problems. The charge and discharge process for the implementation of expense controls and protection of termination of discharge voltage, temperature protection, protection against overcurrent, while the charging process by the cell voltage below represent the monomer flow balanced approach so that the series voltage at the battery terminals of each cell line alone, in order to avoid the state of each cell only difference battery life impact. Sony VGP-BPS10A Sony VGP-BPS10A/B

 

The system of 10 batteries 20Ah in test series, using 5A load at constant current 2A represent a balanced circulation system form a balanced flow of the effect is very obvious that no additional heat, but also to facilitate the ‘energy saving control.

 

Many factors affect the resistance to change, especially the resistance of the internal battery within the whole life cycle variation of the study requires a lot of experiments, the experimental program under way, including the rejection a stack of a simulated operating conditions throughout the life of the testing process.

 

5 Conclusion

 

Before each charge, during and after the load sensing and recording the process of collecting the amount of battery voltage, current, resistance, battery temperature, charging time and other parameters to calculate the amount of each parameter change and changes in rates and with the original presets to compare accurately to assess the ongoing performance of the battery, the size of the warning of possible security problems when using battery Rechargeable batteries provide high security protection. With electric vehicles, for example, even if there is warning battery safety, the driver has at least a few days of free time to deal with maintenance, rather than forced to disconnect immediately.

 

The process of charging the lower voltage batteries make up the monomer flow equalization charge, reducing the difference between the status of each single battery to improve battery life, while avoiding the burden of balancing the balance of the circuit During the heating problem significantly improve the ability to balance, high capacity, high power applications the battery has a significant effect. Inspiron 640m battery Inspiron E1405 battery

 

A complete record of the process of charging the battery charging process for each volume, voltage, current, resistance, battery temperature, charging time and other parameters, which records the rechargeable electrical parameters of the life cycle process of change for Battery Failure Analysis Group provides a database.

Since 1992, benefits of Sony lithium-ion batteries to achieve industrialization since, under its high specific energy, long life, no memory effect, safe, reliable and can quickly load and unload, lithium-ion batteries are become the new power technology recent years, development of hot spots. Lithium-ion Dell Latitude D810 battery is the green environment-friendly pollution free rechargeable batteries meet environmental needs of national energy today in all areas of use of life is increasing rapidly. Currently, lithium-ion has been widely used in mobile phones, laptops, digital cameras, MP3 and other electronic products, many of replacing nickel-cadmium batteries and nickel-hydride batteries, metal, in applications such as most as an exclusive Jiucheng. In addition, lithium-ion battery electric vehicles in recent years, and some other high power batteries have started to come into practical use.

 

Before 2000, the Japanese lithium-ion batteries dominate the world, and production accounting for about 95%. In recent years, with China (including Taiwan) and the rapid rise of South Korea, the Japanese show a single model has been gradually broken. Market Share of Japanese lithium-ion batteries has fallen below 60%, about one third of the world to form a pattern. Although in 2008 the global financial crisis hit, but rechargeable batteries, regardless of volume, sales were both up there on the rise, but this year will continue to be a difficult year. The future, the rapid development of a variety of electric vehicles, lithium-ion batteries will become a major driving force for progress.

 

The status of lithium-ion batteries can not be shaken

 

In 1989, the small size of the room-type lithium batteries to achieve a practical use. However, in the summer over a series of batteries for cell phones use lithium overheating in 1989 and caught fire due to an accident in early 1990, the industry uses a cylindrical, hp F2024B battery Rechargeable lithium had a negative attitude towards the prospects for practical application. However, Sony has specialized in the manufacturing technology of energy batteries Sony (Sony Energy Tech) ’s courage to break the deadlock, the same year in February announced the lithium-ion rechargeable battery reached a practical level.

 

Cause of the accident caused by lithium batteries that will be used as anode material for lithium in the charge and repeated discharge, the cathode is the formation of dendritic crystals, so a short - circuit between the positive and negative electrodes, emitting smoke and fire. The lithium-ion rechargeable battery in the positive and negative do not use lithium metal and its positive use of LiCoO2 (lithium cobalt) alloy material, the negative electrode material using carbon type of coke. This ensures the safety of the Dell KD476 battery to reach the cylinders of lithium type.

 

However, the practice at the beginning of the performance of lithium-ion battery was not significantly better than the main competing products - Ni-MH rechargeable batteries. For example, in early 1993 lithium-ion rechargeable battery unit volume density of energy 220Wh / L (This is a diameter of 65mm and 18mm × length value of the cylinder type battery, the same below ), just over nickel-metal hydride batteries 180Wh / height of approximately 20 L%. In addition, lithium-ion rechargeable batteries, there are many shortcomings, such as “there is no tension between compatibility and dry,” the difficulties of load control “,” high resistance, current high charging and discharging can be, “difficult to parallel, it is difficult to realize large capacity battery” and so on.

 

However, mobile phones and video cameras and other manufacturers of lithium-ion rechargeable VGP-BPS9A/B battery features lights a little low. Energy density per unit weight of these terms, lithium-ion battery than nickel-metal hydride rechargeable batteries is about twice as high as up 115Wh/kg. In other words, the same energy capacity, lithium-ion battery reduces the weight by about half. Thus, manufacturers of portable equipment, under a special favor in 1991 after the adoption of lithium-ion rechargeable batteries have the product market, and very popular. Since then, Matsushita Battery Industrial Company in 1992, Japan’s Battery in 1993, Sanyo Electric, Hitachi and Canada Moli Energy (1990) were commissioned in 1994, established the lithium-ion rechargeable batteries in portable electronics on the market can not shake the position.

 

Since 1990, lithium-ion rechargeable batteries have been largely along the high density and secure the development of these two main lines. To promote the products of small and light, manufacturers of portable electronic equipment urged to improve the energy density of batteries. However, the denser the smoke of the fire, the greater the risk. Incident does not happen again! The summer of 1989 fire incidents in the apple A1060 batteryof technical persistent spirit: If an accident, the use of materials of lithium battery will be the future is doomed.

 

To this end, in lithium-ion rechargeable batteries, the beginning of practical use, the battery manufacturer for its implementation will be known as the “most protective” of strict security measures. In order to fall in poor operation of the battery due to excessive discharge / over charge of the state can ensure security, the manufacturer of the battery configuration of the three types of security architecture: PTC (positive temperature coefficient) thermistor valve Security diaphragm. When mounted detected an abnormal temperature, the possibility of cutting off the electric mode of the load cell to avoid the danger.

 

In addition, development of mobile phones, cameras, computer hardware manufacturers have to ensure mobile security battery has played an important role. At that time, all the hardware manufacturers have established programs for acceptance testing, such as nail prick test, high temperature / low temperature test, as well as heating pan tests. Equipment manufacturers will be a series of tests based on the results raise the existing problems in the toshiba PA3591U-1BRS battery manufacturer, on how to improve the cell structure and design of safety circuits, and so many points of view. In the hard work in close cooperation with the early 20th century during the period, lithium-ion rechargeable batteries are no longer a major accident, the market is developing very well.

 

Improved security, the lithium-ion battery energy density of the battery continues to increase. The beginning of practical use in 1990, lithium-ion battery density of energy per unit volume, but 190Wh / L to 19 years later, in 2009, this value increased about 4 times, reaching 740Wh / L. But the same period, the microprocessor clock frequency up to 100 times the capacity of the DRAM is increased 250 times. Therefore, the rechargeable battery is also frequently called progress is too slow.

 

Increased energy density is mainly based on positive and negative materials to improve hp Pavilion dv4 battery of structural adjustment and improvement of manufacturing processes such as leather and complete been piecemeal. 19 years, there have been three times the material of great change, many, many times the energy density of high speed. The first took place in 1994 and 1995, the anode material of coke in a class of carbon materials, carbon, graphite type materials, this change so that the energy density has increased by about 20%. In the following 8 ~ 9 years, has maintained a positive use of LiCoO2, cathode graphite using a combination of such carbon material. The Change 2nd occurred in 2002 and 2003, the LiCoO2 cathode material in the LiCoO2 and Li (Ni-Co-Mn) O2 mixture of materials, the energy density of about 10%.

 

Is currently in 3rd period of change. The anode material is the reform candidate materials, including the type of silicon alloy, tin alloy and lithium three categories. An alloy of tin came in practical use. Sony introduced after the spring of 2005, the group of device battery has started to use this material. 14mm (diameter) x 43mm (length) of the unit cell volume of the energy density can reach 478Wh / L, compared to traditional materials, an increase of approximately 20% of the Dell Latitude D410 battery.

 

In January 2007, Matsushita Electric Industrial and Matsushita Battery Industrial through the use of certain types of materials such as alloy anode material, with successes to 740Wh / L energy density per unit volume. The company did not disclose the specific circumstances of this alloy material, until March this year, not mass production, it is expected that the near future or will be put to practice. In addition, the type of alloy of silicon and metal lithium as a cathode can significantly increase the energy density of batteries are also on trial.

 

After 2006, laptops and mobile phones and other products used in lithium-ion rechargeable batteries, the recurrence of an abnormal occurrence of heat, the potential fire hazard. Sony, Matsushita Battery Industrial, Sanyo Electric and other battery manufacturers have a large number of recycling batteries. The reasons are said to be mixed in the process of manufacturing powder metal, it is said to be load and unload equipment manufacturers in the management of misconduct. And equipment manufacturers face the cons, up another case of malfeasance.

 

In fact, the real reason not yet been identified. To this extent, must be carefully verified reason, understand that the resurgence ‘accident, the future is doomed, “the gravity of technical staff to learn both sides to ensure safety at all costs try to develop the spirit of time, work together to move forward together.