Digital battery

1 Introduction

 

With the construction and development of communication networks in order to solve the blind spot coverage of the network, has emerged a large number of base stations, outdoor and outdoor-type communications equipment. Because these facilities long-distance communication in hostile environment external communication equipment necessary for the uninterrupted supply problem has plagued the industry is a major problem. IBM ThinkPad T42 battery IBM ThinkPad T43 battery

 

Power of communication itself can in principle respond to the harsh environment outdoors, the real bottleneck is to use external battery. Battery outdoors in the difficulties of current installation, easy to fly, and the battery life is particularly affected by temperature. How to solve the impact of the external environment of the battery, extending its life is essential. The technology used in the comparison of several methods of storage battery in the open air on the method proposed underground ventilation battery type, design, application of the breakdown of battery cabinets underground, outdoor power supplies combined with the enhanced surveillance system to solve the temperature outside the impact on battery life as well as the underground Cabinet battery may experience problems in the wet gas exchange.

 

2 The purpose and significance

 

Underground battery cabinets, ventilation air could solve the outdoor base station uninterruptible DC power issues, increasing the lifespan of the battery to external power, reduce the use of integrated cost of base station outdoor, overall energy consumption for communications equipment outdoors for long outdoor use has opened a feasible way. IBM ThinkPad T60 battery IBM thinkpad r60 battery

 

3, the situation at home and abroad

 

Underground battery for use at home and abroad have reported, but buried in the wet gas corrosion of the battery cabinet batteries, thus reducing the issue of battery life. For this question, there is no good solution. The methods described in this document by the communication power of the system of supervision, the cabinet humidity control intelligent battery fan ventilation underground battery, thanks to the effective implementation, the better for resolve this problem battery life, improved significantly. The technology is still blank in China, the promotion of greater importance.

 

4 The general idea

 

(1) battery-buried form of telecommunications equipment in the solution of the problems of supply, ensure better security, the effects of dust, reducing the effects of outside temperature on the battery life, autonomy extended battery. FRU 92P1141 battery IBM ThinkPad R32 battery

 

(2) Battery cabinet buried the versatility of 2V or 12V battery, the battery life 2V to 12V battery, the basic methods are used underground 2V battery.

 

(3) Through the underground cabinet ventilation fans installed battery airways, humidity sensors, humidity cabinets to collect data.

 

(4) By the communication power of the monitoring unit monitors the battery drawer of the moisture indicator on the frequency of ventilation.

 

5. technical programs

(1) Battery box material selection and processing structure

Taking into account the battery case long buried in moist soil, must be made using the plastic box. Meanwhile, because a larger boxes, more specifications, not by the method of injection molding, welding sheet metal uses. Thickness is 12 mm to 15 mm.

 

(2) The placement of the battery and support

Given the plastic box from the battery itself is strong enough to hold the battery so that the bottom of the battery box with plastic flatbed platform to support the weight of batteries. If the site is not convenient for masons work can also be prefabricated concrete slabs. IBM ThinkPad R40 battery IBM ThinkPad X60 battery

 

(3) The waterproof battery box

The battery box is sealed by welding to achieve the goal. Between the battery box and cover with waterproof tape, and adoption of appropriate measures to waterproof tape attachment compression to achieve the goal of sealing. In addition, the battery box, the lid and connecting PVC pipe with a welding method.

 

(4) Battery box, air cooling

The battery in the trial of a small quantity of gas, the battery box will be acid gases, moisture, the need to unload. First, through the intake pipe, the exhaust pipe of the agreement itself, can achieve natural breathing. In addition, fans have been installed in the exhaust pipe end by means of dry contact connection, control switching power supply of the independent monitoring unit, about 10 minutes a day and regularly required traffic, which can discharge the battery box of sulfur dioxide, moisture.

 

Food switching by an independent external monitoring unit, to facilitate the implementation of control of the fan. toshiba pa3285u-2bas toshiba pa3285u-2brs

To prevent debris through the intake manifold, exhaust pipe in the casing of the battery in the intake manifold, exhaust pipe exits insect net.

 

(5) Security issues battery box

With the battery box and the lid is installed between the access control, battery and cover separation, may alarm.

 

6 Economics

 

General installation and underground installation, there are many gaps in comparison, for example: ① general safety problem of installing the most difficult questions; ② existence of the H rod bearing common installation problems; ③ Installation The most common can be used 200Ah battery, and buried the installation did not have this restriction.

 

7 Conclusion

 

From the above analysis we can see that the battery cabinet, the ventilation of underground air to save 10,325 yuan per year per site, if the new 200 site in Longyan annual basis, the annual investment will allow save 10,325 yuan × 200 sites / site = 2.065 million yuan. toshiba pa3285u-1bas toshiba pa3285u-1brs

 

With the development of mobile services, the number of stations will be outdoors more and more is spent batteries in outdoor conditions is increasing. According to the construction of the current speed of Fujian Mobile, the new stations marginal 2000, if the battery used in all ventilation systems underground Fujian Mobile and annual savings will reach 20.65 million yuan investment.

 

Increasingly tight energy supply in the current international situation, China has strongly advocated the conservation of energy. Underground ventilation air through the use of how the battery cabinet, battery life or more than 3 times the initial rise, each site can save each year to reach million more than expenditures. If a promotion at the national level, the state will save a lot of resources, promotion of high value. toshiba pa3191u-4brs toshiba pa3284u-1brs

The main units of the national production of the electrolyte Jiangsu Guotai (002 091) Wing Wah, Cathay Pacific, Taurus Tianjin, Dongguan Shanshan Shantou Golden, Zhuhai race Wei Electronics, Guangzhou Heaven, Beijing Chong Asia more than 10 products companies chemicals. Annual production capacity of 1000 tons and more are involved in high, middle and bottom of each market to meet our need for production of lithium-ion battery, and some for export. Sony vgp-bps13/s battery Sony vgp-bps13a/b battery

 

Cathay Pacific Wing Wah is a lithium-ion battery electrolytes leading companies in the industry, is the largest manufacturer of electrolytes in lithium-ion batteries. In 2008, the company built in the Jiangsu Yangtze River Chemical Industrial Park has 50 million tons production (also reserved capacity of the plant to 5,000 tons), construction of the plant was completed, in 2009 June-July, the production of 10 trials in November with full production, after production capacity of 3,000 tons of old factories closed. 9.8 had an annual production of 2700 tons / 4000 tons. Currently the company of domestic market share of 30% -40%, and the location of high-end market. Taurus Tianjin, Dongguan Firs 30% of total market share of the product is mainly located in the low-end market.

 

Race Wei Electronic - Zhuhai race Wei Electronic Materials Co., Ltd. is located in Doumen District of Zhuhai City, Toyama Industrial Park, is a new high-tech company and a private investment in new capacity for annual production of 10 million yuan to 1,000 tons of lithium batteries, lithium-ion battery and super production line of electrolytic capacitors, the factory covers an area of 3,000 square meters, produces and sells functional electrolyte batteries for lithium-ion batteries to improve high temperature performance, safety and low temperature properties such as batteries and lithium ion polymer electrolyte batteries, tailored for the lithium manganese oxide, lithium iron phosphate, ternary materials, modified graphite anode natural and cathode materials, electrolyte. Sony vgp-bps13b/b battery Sony VGP-BPS14/S battery

 

Taurus Tianjin - Tianjin Taurus Power Materials Co., Ltd Xingtai Mining (Group) Co., Ltd. and Tianjin Chemical Engineering Research and Design Institute organized jointly funded R & D, production, operation and business services high technology. A completed set of the production of salt electrolyte, solvent refining, the preparation of electrolytes and packaging production line, the main products are: lithium hexafluorophosphate (scale of 80 tons / year), High purity solvents (scale of 500 tons / year), the lithium-ion battery electrolyte and related materials. Taurus Tianjin Company is the only means of self-developed technology, and national production of raw materials and office equipment lithium hexafluorophosphate, but with feedback from the industry, quality products and the internationally, there are still a big gap.

 

6 hexafluorophosphate lithium raw material supply

 

The main raw material for the lithium salt electrolyte, the scientific name (lithiumfluorophosphate LiPF6), which represents about 50% of the cost of its production cost is 10 yuan / ton, a price of 400,000 yuan / ton Gross margin was 75%. Silica materials of lithium carbonate lithium / can be purchased in China. Sony VGP-BPS18 battery Sony VGP-BPL12 battery

 

Lithium salt is now almost monopolized by a handful of Japanese companies. Among them, the annual production of electric Kanto Chemical LiPF6 to 950 tons (mainly for UBE) SUTERAKEMIFA 800 tonnes (mainly ECOPRO), the world’s largest manufacturer of lithium salts to produce 960 tons of chemicals Morita (mainly for Mitsubishi) The company in Jiangsu Yangtze River Chemical Industrial Park has an annual production of 600 tonnes of production lines, including 300 tons of supplies from the company. There is also a Golden Tech Co., Ltd., Tianjin Chemical Engineering Design & Research Institute, Shandong Chemical Fertilizer Xingtai city, Tianjin, Taurus and other businesses to produce, but less capacity, quality and are much worse.

 

Because lithium hexafluorophosphate huge future market demand, domestic firms have begun to actively access the other. Jiangsu Guotai (002 091) and subsidiary Huarong established jointly funded source of high-tech materials Zhangjiagang Asia Co., Ltd., has invested an annual production of 300 tons of new products lithiumfluorophosphate project a total investment of 83.3 million yuan , is expected before the end of 2009 the test equipment to debug. Henan Fluoride Chemical Co., Ltd. started construction in 2009, the annual production of 200 tons of projects lithiumfluorophosphate Sony VGP-BPS7 battery Toshiba Satellite A80 battery

 

7, the next significant increase in the electrolyte Market Forecast

 

1, hybrid vehicle market

 

Hybrid Electric Vehicle (HEV) in the coming years the main developments in the direction new energy vehicles. 2010, global oil production will reach 78 million vehicles, hybrid electric vehicle production will reach 2.1 million or 2.66%, each battery of the vehicle to 50,000 yuan, and the overall battery market value of the car would be 105 billion yuan. Most auto manufacturers of hybrid cars to 85% Ni-MH battery energy storage devices for vehicles. But the big manufacturers have new models in the use of lithium batteries as the energy storage of the vehicle. Li-ion battery to replace nickel metal hydride being is likely to accelerate faster than the market expected. (For Foton Motor, for example, received 800 new hybrid vehicles, has decided to all use lithium batteries) lithium vehicle battery to the industrialization of the rapid penetration of 20% in terms of products, the magnitude of the market should reach 21 billion yuan. Corresponding to 2.52 billion yuan market scale in future large-scale commercial demand HEV electrolyte is expected after the explosive growth of the electrolyte. apple ibook g4 14-inch battery apple macbook 13 inch battery

 

2, the market for electric motorcycle

 

In 2008, world production of over 22.5 million electric bikes, of which 95% is produced in China. In common usage the battery electric bike, 84% of lead acid batteries, lithium battery with only 14%. According to estimates, in 2010, world production of electric bikes is nearly 30,820,000, the output value of the battery reaches 61.64 billion yuan, if the lithium penetration reached 10% of span market expected to reach 6.164 billion yuan, the corresponding size of the market to 740 million of electrolyte element.

 

3 wheelchair market, scooter and

 

Electric scooter, including golf carts, electric wheelchairs, 2007, worldwide sales approaching one million electric scooter, the rate of about 8% annual growth expected to reach 1.2 million in 2010. The market is dominated by lead acid batteries, but also the direction to the development of lithium-ion batteries. Projections for 2010, global demand for the scooter more than 1.2 million euros out of the battery will be nearly 3.3 billion dollars if the penetration rate of 10% lithium wide market expected to reach 2.975 billion yuan, the corresponding size of the market electrolyte 120 million yuan. apple a1189 apple ibook g4 12-inch battery

 

4, the power tools market

 

Power Tools is a broad application prospect of the lithium battery market. Currently, power tools, mainly nickel-cadmium batteries, power tools with lithium batteries can easily see through in the past 18V voltage design constraints, and trends of an industry first product tool. 2005, E-ONE Moli and the launch of the V28 Miwaukee used cathode material for lithium manganese industry power tools, 26,650 sessions of shock caused by the formal declaration of power tools lithium era. In 2007, the world’s largest power tool manufacturer B & D introduced the first use in the world of power tools lithium iron phosphate (DCX6401 Combo kit), following the announcement of this product in the first two quarters, then his 1-hour fast charge, powerful, high security, and more than 2,000 times the cycle life of the battery and other benefits, a record 20 million in sales performance, breaking the B & G since the foundation of all records. In the promotion of international manufacturers, the penetration rate will increase lithium. The current global demand for power tools around 5% growth rate per year, power tools, lithium battery for less than 10%, 85% of nickel-cadmium batteries. The nickel-cadmium because of pollution problems, the European and American countries have gradually legislation to restrict the scope. According to estimates, in 2010, the global energy market tool will reach 182 million units, demand reached 730 million batteries, battery production will reach 33 billion yuan, if the penetration rate reaches 10% lithium market reached 3.3 billion market sizes of 396 million euros corresponding to the electrolyte, next year there will be a steady growth. apple a1148 apple a1175 apple a1185

1, the profile of lithium-ion battery electrolyte

 

The electrolyte is a lithium-ion four core subjects (cathode, anode, separator, electrolyte) one, known as the lithium-ion “blood,” Chiang Kai-shek to the battery negative role of electrons conduction from the game, a lithium-ion batteries have been high-voltage, high specific energy and other benefits of the warranty. Electrolyte solvents of high purity generally organic electrolyte lithium salts (lithium hexafluorophosphate, LiPF6), the required additives, raw materials, under certain conditions, formed by a certain percentage of the preparation. VGP-BPL11 VGP-BPS12 VGP-BPS14/S

 

Secondly, the types of electrolyte lithium-ion

 

1, the liquid electrolyte

 

Selection of the electrolyte on the performance of lithium-ion batteries are very large, it takes a good chemical stability, especially in high potential and high temperature environment less prone to breakdown, with a high ionic conductivity ( > 10-3 s / cm), and the anode and cathode materials must be inert, they can not invade the rot. As the battery lithium-ion battery and discharging potential and the anode material with a high chemical reactivity of lithium, the electrolyte must not contain water with organic compounds. However, the ionic conductivity of organic matter are not good, then soluble in organic solvents by adding salt to increase the conductivity of the ionic conductivity. Current lithium-ion batteries are mainly used liquid electrolyte, the anhydrous organic solvent such as EC (ethyl carbonate), PC (propylene), DMC (dimethyl carbonate), DEC (diethyl carbonate), the majority of solvents mixed, such as EC2DMC and PC2DMC. Conducting salt with L iClO4, LiPF6, LiBF6, Lia and SF6 LiOSO2CF3, the order of their conductivity LiAsF6> LiPF6> LiClO4> LiBF6> LiOSO 2CF3. Due to the high oxidation LiClO4 prone to outbursts of security issues, generally limited to experimental studies, easily purified LiAsF6 high ionic conductivity and good stability, but contain toxic, restricted use; LiBF6 Chemistry and good thermal stability and conductivity is not high, Lio SO2CF3 low electrical conductivity and corrosion of the electrodes are under appeal; Although LiPF6 decompose, but with a higher ionic conductivity, until the lithium battery ion is to use LiPF6. Current commercial lithium-ion battery electrolyte used in most cases the LiPF6 EC2DMC, it has a high ionic conductivity and good electrochemical stability. VGP-BPS10A/B VGP-BPS10B VGP-BPS11

 

2, solid electrolyte

 

Directly with lithium metal as anode materials with high reversible capacity, the maximum theoretical capacity of 3862mAh · g-1, is a graphite material 10 times, lower prices, is considered a new generation of lithium-ion batteries The most attractive anode, but to produce lithium dendrites. Using solid ionic conductivity of electrolytes such as lithium may inhibit the growth of dendrites, which makes it possible for the anode materials of lithium. In addition, the use of solid electrolyte leakage of electrolyte fluid to avoid the shortcomings of the battery can be thinner (thickness of only 0.1mm), higher energy density, smaller batteries of high energy. destructive experiences show that security at the solid-state lithium-ion battery is high, nailing through the heating (200 ℃), short circuit and cooler (600%) and other experience destructive, the liquid leakage of electrolyte lithium-ion occurs, explosions and other safety issues, and cells in solid within the temperature slightly higher than outside (< 20 ℃) there are no other safety issues. Solid polymer electrolyte has good flexibility, film formation, stability and low cost, both positive and negative electrodes as an electrolyte membrane with the ions can be used as a transfer. VGP-BPS13/S VGP-BPS10 VGP-BPS10A

 

solid polymer electrolyte can be separated into dry form solid polymer electrolyte (SPE) and gel polymer electrolyte (GPE). SPE solid polymer electrolyte are mainly made of polyethylene oxide (PEO), the drawback is a lower ionic conductivity at 100 ℃ can reach 10-40cm. ion conduction in the SPE is primarily in the amorphous region, with the movement of polymer chains pass migration. Easy crystallization of PEO molecular chains because of its great regularity, and crystal technology to reduce the ionic conductivity. Thus, to improve the ionic conductivity of one hand to reduce the crystallinity of the polymer chain mobility increases, the other can improve the conductivity of salt in the solubility of the polymer. The use of graft, block, crosslinking, copolymerization and other means of destroying the crystallization properties of polymers can significantly improve the ionic conductivity. In addition, complexes of inorganic salts can be added to improve the ionic conductivity. In the solid polymer electrolyte by the addition of high dielectric constant of the liquid low molecular weight organic solvents such as PC can greatly improve the conductivity of the solubility of salt, the composition of the electrolyte is PEG polymer gel electrolyte, which in high ambient temperature ionic conductivity, but the process will be in the use of liquids and failure analysis. Gel polymer lithium-ion batteries have been commercialized. Sony VGP-BPS12 battery Sony vgp-bps13 battery

 

Third, the tendency to develop electrolyte materials

 

Lithium-ion battery with its own full benefits is in a much larger group of industries - from automotive battery in the field. To respond to this great group of industries, materials for lithium ion electrolytic future trend of development will focus on new solvents, ionic liquids, additives, lithium salt Deng Fang Mian, and the new Zheng Xiang Pipei equipment negative if the lithium-ion batteries safer food, higher, capacity, security and ultimate convenience applied to electric vehicles, energy storage, aerospace and larger area.

 

Industry lithium-ion to meet the needs of future development, we must develop a high-security, high environmental adaptability of electrolyte materials of the battery. Mostly electrolytic solvent, the choice of solute and additives for consideration:

 

(1) to select a wide range of working temperatures of solvents, melting point solvent of the best from -40 ℃ below the boiling point preferably above 150 ℃ or more, wide electrochemical window solvents better prevent the state of charge under the redox electrolyte, while the cycling stability can increase the battery. For example, consider the use of ionic liquids, a new solvent, multi-component solvent, so as to solve the battery of safety and adaptability of the environment. apple powerbook g4 17-inch battery apple macbook 13 inch unibody battery

 

(2) Select the appropriate fluid to improve the battery to the environment. Now commonly used LiPF6 (lithiumfluorophosphate) decomposition temperature is low, 60 ℃ and a small amount of decomposition at high temperatures or in harsh environments, the decay has significantly increased, resulting in HF (hydrofluoric acid) and other free acid to acid electrolyte, the electrode material, causing damage and rapid deterioration of battery performance.

 

(3) may consider adding the right amount of flame retardant additives, redox shuttle additive to protect the positive and negative film-forming additives. Flame retardant additives can be used to ensure that the internal battery thermal runaway, the electrolyte does not burn a fire, so the battery safety can be guaranteed. With the role of the redox shuttle additive is to prevent, especially when the battery battery during use due to abnormal conditions, single battery charge would be too frequent or too high, causing rapid deterioration of performance battery, which affects the whole group’s performance and battery usage, and even the occurrence of a security risk. With a film positive and negative is the role of additives that can effectively protect the anode and cathode materials and electrolyte in the charged state of the reaction of contact, through the film as a high degree of activity is negative and the electrolyte to be isolated to prevent the electrolyte response to the surface of the electrode. apple powerbook g4 12 inch battery apple powerbook g4 15 inch battery

 

Fourthly, the development of the global situation of the electrolyte of the lithium-ion

 

In recent years, the global lithium-ion battery electrolytes stable industry, the market mainly in Japan, Ube Corporation and ECOPRO (Cheil City) Company, the two companies represent approximately 50% of global market share. Filed in the following companies as follows: Mitsubishi Chemical, Toyama Chemical, Mitsui Chemicals, Kishida Chemical, Zhangjiagang Guotai glory and other businesses.

 

Fifthly, the development of the internal electrolyte of the lithium-ion

 

Made of electrolyte to penetrate the market in 2002 to gradually replace imported products, through continuous improvement and product quality has reached international advanced level. Currently supports the manufacturers of electrolytic cells were localized mainly use imported only a small portion of the electrolyte. apple macbook pro 15 inch battery apple macbook pro 17 inch battery

4 single cells linear charge voltage limit advanced control

single cell have been sampled by the voltage control circuit of each cell, through or remove a single cell maximum gate voltage after the signal conversion circuit in the control circuit of the limited pressure circuit control limits of power management voltage by dynamically adjusting the impedance control of lithium-ion battery voltage of the single cell. If neither a single cell voltage reaches the value set, the solar panel to the relatively stable current through the pressure limiting control circuit in the power management of the lithium-ion battery charging, management Food of the impedance is close to zero, when everything just a single battery voltage reaches the set value, increases the impedance of the power transistor, battery charge current decreases with decreasing load current by laws characteristics of lithium-ion decision (approximately exponential). This circuit has the advantage of a constant voltage charging phase of the continuous flow decreases, essentially exponentially, compared to adapt lithium-ion battery charging habits, the load circuit power as well. Dell Vostro 1220 battery Dell Vostro 1220n battery

 

Several load equalization technology

 

A shunt resistance constant load balanced

 

All Lithium-ion single time on a shunt resistor in parallel. As can be seen on the circuit, the current shunt resistor must be greater than the battery self-discharge current to reach the equilibrium charge effects. General lithium-ion battery self-discharge current C/20000, it is flowing through the shunt resistor on the current catch C/200 is more appropriate.

 

In addition, the difference of each resistor shunt is also an important factor affecting equalization. After a number of charge cycles and discharge gap of a single cell can be determined using the following formula:

gap V battery voltage = I × R shunt one battery discharge gap 2 × V × K resistance

If the shunt resistor to 20Ω ± 0.05%, the bias voltage of the battery to control the range 50mV. Mean power of each resistor 0.72W, but whatever the battery charge or discharge the battery, always consume power shunt resistor. Dell Inspiron 1470 battery Dell Inspiron 1470n battery

 

Level 2 charging off-balance sheet resistance shunt

 

resistance segregation of charge balance and exceptional charge the difference between equilibrium segregation resistance is increased by a switch off, the switch can be controlled by a software system computer to achieve, but also a simple logic circuit can be achieved. This control method uses a balanced circuit in the perception of constant tension working TYPE section, other times switch broke, it needs to discharge the battery, the shunt resistor does not consume valuable energy. In the phase of light, the solar power generation, there is a surplus, and consume little energy for the balancing system of the supply circuit for a certain rationality. In the orbit of satellites in low orbit, the circuit balanced only 10% of working time in order to obtain a balanced effect discussed above, the value of resistance must be reduced by 10 times, shows the peak power thermal is very high, this circuit is the main drawback. In addition, the effectiveness of extinguishing a fatal failure, redundancy means must be used. Dell Inspiron 14z battery Dell Inspiron 1570 battery

 

Switched-capacitor charge balance 3

 

principle switched capacitor charge balance in Figure 7, we can see from the figure, the order of the circuit control switch is composed of clock circuits, causing a closure order multi-switch, the order to send a capacitor of the lithium-ion single entry by sending imbalance between the energy of a single cell to achieve the goal of equalizing charge. At the same time, by measuring the voltage on the capacitor voltage sent to monitor every single cell. If one cell short-circuit failure, low voltage output of the comparator switching prohibition to prohibit access to short-circuit transfer capacitor cell to eliminate the influence of the work of bodies unicellular others in the same time for constant voltage converter in a constant current battery low voltage alarm, so that constant current constant voltage converter circuit according to the situation of a single cell to determine the correct constant voltage. The biggest advantage of this symmetrical circuit is very low energy loss, a disadvantage is that circuit complexity, multi-switch on resistance, high common-mode limit will affect the achievement of a balanced load. On the other hand, the selection of parameters is difficult to configure different power system, the circuit parameters of the detailed design and verification requirements, which is detrimental to the development cycle. Dell Inspiron 1570n battery Dell Inspiron 15z battery

 

4 buck converter load equalization

 

Buck converter is also a balanced load of a balanced program of low consumption. It is a very clear idea of the main circuit is a standard buck regulator, the inductor energy to increase the subgroups of the same winding, the auxiliary monomer to charge the battery. Clearly, low voltage single cell will get more energy second winding, the high voltage energy to get less, if the goal of achieving a balanced load. To get a good balance of effects, sub-winding consistency requires strict control. However, the consistency of the inductor winding is very difficult to control, if it is one of the biggest weaknesses of control like. This study has just started charging, the charging efficiency, balanced results, reliability analysis requires further study.

 

The average balance of cell charging voltage 5

 

The average cell voltage balance charging principle illustrated in figure 9, the figure only shows a single cell in a symmetrical circuit, the other single cell is also equipped with the same balanced circuit, which, starting from a single amplifier cell. dell latitude d810 battery dell latitude d820 battery

 

The control circuit of load balancing of thought is as follows: single cell voltage and average voltage of a single cell from the control switch to the battery voltage is higher than the average single cell voltage of the shunt. Therefore, all voltages unicellular symmetrization of the average voltage of a cell under trend.

 

At first glance, this circuit is the open loop control, in fact, the internal resistance of the battery as the role of balanced circuits work in a negative feedback loop characteristic states. Balanced to avoid work-circuit the battery discharge, the power switch in the bottom of the diode series regulator, so that the discharge of the battery, the battery voltage is low and the loss branch circuit. dell latitude d620 battery dell latitude d800 battery

 

The model of the average cell voltage balance charging circuit is a comprehensive study, is considered a highly effective program. This circuit has been included in the orbit of LEO satellites of choice for applications in lithium-ion program, has filed patents in France and Europe.

 

Conclusion

 

Discussed above, the lithium-ion battery charging circuit management key technologies: constant current - constant voltage (cone) the method of load and load-balanced technology. In comparison, our point of view, the “single-cell linear voltage peak” limiting load control programs more compatible with the use of small satellites, can avoid the pass-type control consumption of significant heat, “Split”, a huge pulse of current load control, “subtype” constant voltage charging phase of the load current reduces the gap discontinuity, the average cell voltage balance charging circuit adaptable all indicators are ideal. dell latitude d600 battery dell latitude d610 battery

Lithium-ion storage device of energy for development of the probe is the third generation storage device probe energy. It has a light weight, small volume, no memory effect, the benefits of temperature adaptation in width, the main use of nickel-cadmium batteries, replacing the nickel-hydrogen batteries. Lithium-ion batteries for the ratio of the weight of aerospace may be 90 ~ 110Wh/kg, compared to 45 ~ 60Wh/kg NiMH battery indicators have obvious advantages. However, the electrochemical properties of lithium-ion battery charging process requirements must be strictly controlled, therefore, to design a special charging circuit management to control the spacecraft charge lithium-ion batteries. Dell TD347 Dell U4873 Dell D5318

 

The key technology of lithium-ion

Li-ion replacement battery Ni-Cd, Ni-MH battery can be applied to a simple plug and play “approach, because the lithium-ion and nickel-cadmium, nickel-hydrogen batteries have one of biggest differences: overcharging lithium-ion is strictly prohibited. Therefore, we must combine the characteristics of the circuit design of new lithium-ion battery management. Lithium-ion battery management circuit of Battery critical point (with Ni-Cd, Ni-MH battery charge management circuit main difference) are mainly two aspects: the burden and load equalization.

 

In engineering applications, the battery cell lithium-ion batteries in parallel from a single monomer or composition of the battery module in the battery must be serial, consider the process of recharging the battery or monomer imbalance battery module, and over time, these imbalances will become increasingly serious, serious impact on battery life and reliability, thus equalizing charge is the key technology of lithium-ion battery. Dell HD438 Dell Y9943 Dell FK890

 

A constant current - constant voltage (cone) Charge Control Model

The use of nickel-cadmium, nickel-hydrogen satellite battery power system, essentially using constant current charging mode, when reached VT curve, power electronics, pressure, third mode control electrode to stop charging when the control point, completion of a load. control lithium-ion battery is not suitable for the use of these methods because they do not warrant charges the rechargeable lithium-ion is still limited to the final pressure within prescribed limits, even if the voltage final charge is guaranteed, in general, immediately after the pressure reaches the final charge stops charging, the rechargeable lithium-ion batteries to reach the final after fracturing still need to add capacity by 30%. Years from lithium-ion battery development for the constant current - constant voltage control load is the most common and most suitable for the load control method. In this mode, the first battery charger lithium-ion battery for constant charging current when the battery voltage increases gradually, when the battery voltage reaches the value set for constant voltage when the load current decreases approximately exponentially, so that kind of pricing model for load control, also known as the cone. Dell GK479 Dell NF343 Dell PC764

 

Two load-balanced technology

The space should be used with the balance of the lithium-ion battery charging technology, this view has been fully recognized at home and abroad. Technology equalizing charge primarily to address long-term single cell lithium-ion battery charge polarization phenomenon in electrochemical properties, so that the merits of a balanced load takes time, money and labor ie the work can be effectively audit.

 

Rechargeable lithium-ion balancing civilian products in the attention and has not been applied because of the multi-cell single section is rarely applied in series, reliability, life does not ask. The lithium-ion batteries in electric vehicle system, the series of sessions over single cell, have adopted a balanced load technology, generally used for control and SCM systems on a single battery practice shunt resistor control a single battery charge. This approach control complex, inefficient, heat consumption Tai balanced long early Yizhi aerospace production scenario this method, and now foreign technical staff working Tantaogengjia ideal. Dell GW240 Dell RN873 Dell Y6142

 

Importance of the equalizing charge is to make lithium-ion batteries maintain a voltage difference only in the expected range, thus ensuring the life of every cell in the satellite is not subjected to excessive stress at the impact and damage. Without a balanced load control, with the increase in the charge-discharge cycle, the cell voltage gradually unique differentiation.

 

In general, only lithium-ion battery charging voltage is 50mV away is perfectly acceptable. We believe that the main cause is through the efficacy of a single battery charge, the self-discharge rate different. On the other hand, a single cell in the circuit for measuring the current consumption should also seriously consider the impact, sometimes measuring circuit power consumption has reached the magnitude of the battery self-discharge current. life of the lithium-ion experiment, and some technical staff to accommodate the battery first or the last series alone is often the first damage, often caused by consumption as measured circuit. Dell Studio 1435 battery Dell Studio 1436 battery

 

Load control circuit

 

A load control bypass

Light through the diode array of solar charge directly to the lithium-ion battery charging, the battery is in charge of each cell are the branch circuit. When a single cell voltage reaches the set value, the bypass load started turning the power transistor, shunt some of the load current to maintain the voltage of the single cell is a constant in a narrow range. Identify the characteristics of the battery charge current decreases (approximately exponentially) until the end of illumination. This pricing method can not guarantee that any equalization battery single charge, but a bypass circuit of higher power, the load current is difficult to measure.

 

2 Split Load Control

single cell through the various check the battery voltage sampling circuit, respectively, after removing the single cell or a maximum gate voltage, the circuit for signal conversion from the reference signal of error signal The error signal in the circuit shunt regulator, the control group of lithium-ion battery The only tension. Either the battery voltage reaches a set value, the battery charge current decreases on average. Using a switching regulator shunts the constant monomer charge, the charging current is pulsed in order to use the lithium-ion battery need to control the group can adapt to changes in current load. Dell Studio 15 battery Dell Studio 17 battery

 

Main Error Amplifier (MEA) sampling signal bus voltage, causing the error signal sent to the shunt. It is, shunt regulator, along with a bus voltage of the battery and single control voltage of the battery.

 

Paragraph 3 Charge Control

Comparison of single cell from an inspection of the single cell voltage sampling circuit, any one of the single cell voltage exceeds a given value, or the door will produce a transient voltage signal, the circuitry to disconnect throughout the prosecution case locked, which makes the load current drops to third, where once again the signal voltage to generate a second charge to turn the table, until the last turn off the load range. When the load pulse or in the shadow of the coming period, the circuit generates unlock unlock signal circuit load control can make the process of the next refill. Clearly, when the constant voltage, the load current is not similar to exponential, but ladder-type step decreasing. dell latitude d830 battery Dell Studio 14 battery