Saturday 21 november 2009 6 21 /11 /Nov /2009 04:38

maintenance of valve-regulated lead-acid batteries

DC substation equipment, equipment selection and design ideas are constantly changing, especially in recent years, new equipment are being born, DC charging device replacement, made continuously improve the quality of valve-regulated batteries, and related equipment, DC emergence of automatic monitoring equipment DC system for the safe operation of the substation level provides battery for camcordera strong protection. VRLA batteries have been compared in the substation is currently widely used, many people called it as maintenance-free batteries, in fact it is compared with open-type battery of the biggest advantages is to reduce the labor intensity of the battery maintenance, but routine Charge maintenance work is still indispensable. However, as "maintenance free" is a misleading term, allowing the user to relax on the daily valve-regulated lead-acid battery maintenance and management, resulting in reduced battery capacity and damage early. Therefore, we should strengthen the use of maintenance-free battery requirements and maintenance methods of publicity, the correct understanding of "maintenance-free" means to ensure the safety and reliability of DC system.

Affect the life of a VRLA battery the main factors

The normal service life of valve-regulated lead-acid batteries in 8 ~ 10a above, in theory, can be 15 ~ 20a, but in actual use in the often inadequate capacity, or early failure phenomenon. There are many factors affect battery life, but compared to VRLA batteries, the following key factors is the operation most vulnerable to the.

1.1 The impact of operating ambient temperature

Battery at 25 ℃ environment, availability of a longer life. Temperature, the battery will exacerbate corrosion of the plates at the same time will consume more water, thus shortening battery life, long-term operating temperature if the rise 10 ℃, life is about half-way.

1.2 the higher the impact on the battery float voltage

A higher float voltage for the majority of normal cells is undoubtedly in the overcharge condition. There is no doubt that this will generate a large number of O2, H2. In theory, valve-regulated battery is losing water, but the fact is inevitable. First, the re-combination reaction is impossible to achieve 100% efficiency and can not be combined to form the gas in the battery within a certain degree of pressure, the pressure rise above the threshold control valve, the valve opens, the gas discharged from the control valve. Second, the battery is not completely sealed, the battery water loss is a slow process. In the previous battery maintenance, along with a balanced charging process is carried out to adjust the proportion of the battery, that is used to add distilled water method to add water in order to maintain battery balance. However, maintenance-free batteries, in the maintenance of the existing system is not adding water, so a result, water loss will inevitably result in the battery, the battery dry.

1.3 Imbalance of charge and discharge of

The study results showed: grid alloy composition and structure in different parts of the distribution is different, which will lead to the unbalanced nature of grid electrochemical properties, this imbalance will, in turn in the float, and charge and discharge state The voltage generated difference, and will as the charge and discharge the cycle, so that this difference is increasing, and the formation of the so-called "backward batteries (battery failure)." The current domestic standards, in a group of the largest battery fIBM ThinkPad R50 battery，IBM ThinkPad R51 battery， IBM ThinkPad R52 batteryloat voltage difference should be ≤ 50mV, while the developed countries, standards are ≤ 20mV, so attention should be paid and to reduce the floating state battery operating voltage differences.

1.4 thermal runaway phenomenon

As the use of depleted fluid valve-regulated lead-acid battery design, battery electrolyte perfusion are adsorbed on the glass fiber, when the charge current increases, it is necessary to release the gas through the valve, resulting in the battery water loss, resistance by large volume attenuation in the charge and discharge a lot of heat generated in the process, which spread the heat as the temperature was too late surge, they will form a thermal runaway. Thermal runaway causes are not promptly reduced float voltage, lax safety valve or open valve pressure is too low, etc. In severe cases of thermal runaway if the discharge has the potential to transient voltage dip lasting battery and battery housing the temperature rose to 70 ~ 80 ℃, and therefore thermal runaway must be a high level of attention.

2 valve-regulated lead-acid battery operation and maintenance of

In response to these affect the service life of valve-regulated lead-acid batteries analysis of the factors, in order to improve the service life of valve-regulated lead-acid batteries, you must do the following work.

2.1 The strict quality control

In the battery selection and procurement process, we must fully understand the manufacturer's production processes, manufacturing process and quality control methods, as well as technical characteristics and so on, if necessary, require manufacturers to conduct the first in the capacity of experiments to screen a smaller difference in battery.

2.2 The rational choice Charging Equipment

Choose the VRLA battery charging equipment, the appropriate use of high-quality high-frequency switching power supply or a phased power supply, the ripple factor, regulation accuracy and precision of the main indicators of steady flow have higher demands, and should have real-time monitoring and intelligent management capabilities, enabling the work of sealing the battery always in the best condition. For the high-frequency switching power supply module when there is failure, should be able to immediately quit running, and does not affect the normal operation of other modules to ensure the battery is not due to module failures caused by excessive discharge.

2.3 do maintenance work to improve the quality of maintenance

2.3.1 Use and maintenance of new battery

The new valve-regulated battery is put into use, first of all to conduct additional charge (ie, all charge). When the voltage at 25 ℃ for 2 35V / monomer ± 0 02V. Charging time about 16 ~ 20h. If you are not a standard temperature should revise its charge voltage. Only in the case of fully charged battery can be checked against the capacity tests, the battery charge and discharge criteria should be (ministerial standards), due to the battery electrode active material from the surface to be fully within the chemical reactions take some time, so Recommendation 2 times charge and discharge time interval should be larger than 10d (depth of discharge cases). The longer the charging time is relatively deep depth of discharge for some.

2.3.2 On-line battery charging maintenance

Battery in use, it should be in accordance with the manufacturer of rechargeable batteries require battery charging parameter settings. In particular, the current microcomputer-based charging equipment, intelligent manner and extent are different on the valve-regulated battery charging should be able to request the following.

a) VRLA battery float voltage at 25 ℃ 2 25V ± 0 02 / monomer, it is best to take in the 2 25V ~ 2 26V / monomer, that is, slightly higher than the central values.

b) battery systems are often only single cells in series by a multi-use, so the system floating-Chong Chongdian current value depends on the current value of which a floating lower monomer. Under normal circumstances, series system, even if individual monomer higher voltage, but because of float charging current is limited, its maximum value will not exceed the specified value. Therefore, within the provisions of the float current value (usually 2mA/Ah), to suitably increase the float voltage value for the individual is still not sufficient capacity in the midst of the backward voltage of single battery is useful.

c) Unattended station select the value of the float voltage can not be less than the center value, because the user is not always possible on the charge voltage adjustment devices.

d) are charging for the value with the limit switches to automatically determine both the standard rechargeable battery chargers, often in both state of charge after the battery system can not be sufficient capacity. Therefore, when the value of float voltage must be adjusted above the standard values in order to gradually sufficient capacity.

e) to obtain low float voltage will cause a sharp decrease float current, the relative charging time will be extended. If the load changes in time interval shorter than the battery fully charged within a short time, so the battery will be charged less than the battery discharge IBM ThinkPad T40 battery， IBM ThinkPad T41 battery， IBM ThinkPad T42 batterycapacity will become increasingly smaller, while the battery float voltage is too low, the internal plates of lead sulfate synthesis can not fully PbO2 and Pb, long term, the lead sulfate will become the two lead sulfate crystals thick Pb (SO4) 2, the last can not be converted into PbO2 and Pb, which appears sulfate electrode.

2.3.3 periodic maintenance measures valve-regulated batteries

2.3.3.1 on a regular basis are charged. Were charging voltage with 2 35V / monomer ± 0 02V. Every three months to 6 months should have been charging a times, should be considered normal float voltage difference between the degree to decide. Both charging time is generally 8 ~ 12h. On a regular basis are charging objectives are: elimination of temperature changes and failure to make timely amendment to float voltage change; battery float voltage is often discharged, but not within the specified time to its fully charged.

2.3.3.2 on a regular basis to amend the float voltage battery system

Since the battery float voltage of the system influenced by temperature, it should be based on the use of battery systems to changes in ambient temperature and timely amendments to the charging system voltage. Usually adjusted each year to set 2 to 4 times. Adjusted criteria: environmental temperature is increased by 1 ℃, the lower float voltage 0 003V / monomer; ambient temperature decrease 1 ℃ per, the increase in float voltage 0 003V / monomer. Battery in under high ambient temperature operation (greater than 30 ℃), due to battery internal resistance become smaller, the battery charging efficiency, battery capacity will increase. And a suitable reducing float charge voltage value, reducing the float current of the battery capacity is not affected. When the battery is reduced when operating ambient temperature (20 ℃ or less), batteries lead sulfate solubility and dissolution rate of reduction, electrolyte concentration polarization increases, while the electrolyte resistivity change induced by the battery internal resistance increases, thus requiring the at low temperatures have a higher charge voltage, in order to meet charging requirements. Otherwise it will create the phenomenon of charging enough.

2.3.3.3 checked on a regular basis discharge, test

Float a long period of testing battery system work, the negative electrode active material due to over-design and the presence of oxygen-evolving complex, resulting in a total some of the negative plate active material is charged less than the state, but also due to the long float current values are smaller and not enough to make a very board is fully active substances inside the electrochemical reaction caused by the internal electrode active material sulfate, thereby reducing the negative plate capacity, the battery life be affected. To avoid these phenomena, and a floating charge for a long time in the working state  battery for digital of the battery system should be different depending on the work of the state to take every 6 months or 12 months a second check of discharge test. When the 6-month discharge a time when the shallow depth of discharge can be more, should adopt the 30% ~ 40%, if the 12 months to deepen discharge tests may be appropriate to some, should 50% ~ 60%, the depth will be easier to observe post-deepening battery system failure occurs single battery.

3 Conclusion

In short, the maintenance of valve-regulated lead-acid batteries is very important, according to the different characteristics of valve-regulated lead-acid batteries, valve-regulated lead-acid batteries that affect a major factor in life and constantly improve the level of maintenance to achieve the purpose of improving life in order to DC operation of the system to improve the reliability of substations to ensure the safe operation of power grid.

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Monday 16 november 2009 1 16 /11 /Nov /2009 04:58

Catalyst Simulations Could Lower Fuel Cell Cost

Imagine a car, from the operation of solar energy and hydrogen to produce water, rather than carbon dioxide emissions. And as such vehicles will not be on the market quickly, the University of Wisconsin-Madison researchers are gradual, but significant advances in fuel cell technology can be the vehicle of its own realities.

Science and Engineering, Denmark, Morgan, an assistant professor and doctoral Edward (Ted) Holby have developed a computational model that cancamcorder batteries optimize the fuel cell, which allows wider use of this technology an important component. Basically, they study how the material related to the overall stability of particle size, their model shows an increase of the fuel cell catalyst particle size decreases, thereby increasing the degradation of a fuel cell life.

Fuel cell electrochemical device, to promote reaction of hydrogen and oxygen to produce electricity, to form water. Morgan fuel cell research fuel cell proton exchange membrane or proton exchange membrane fuel cell, hydrogen called into a proton and an electron on the fuel cell side (anode). Of protons through the device, but was forced to the outside of electronic circuits, traveling can do useful work initiatives. The fuel cell (cathode) and the other side, protons, electrons and oxygen combine to form water, which is the only waste generated.

Although it sounds very simple premise of obstacles, there is widespread use of fuel cells, efficient production of a few. One obstacle is the catalyst to facilitate between the protons, electrons and oxygen cathode reaction. The current fuel cells use platinum and platinum alloy catalyst. Although the platinum can withstand the corrosive fuel cell environment, it is expensive and not very rich.

In order to maximize the use of platinum, the researchers used the platinum catalyst particles as small as 2 nanometers, which is a diameter of about 10 atoms. These tiny structures have a large surface, which the fuel cell reaction. However, the small platinum catalyst degradation very quickly.

He said: "From the stability of nano-material of thinking is understandable cheese intuition," said Morgan. "When you leave a chunk of cheese to be Dell Latitude D800 battery， Dell Latitude D810 battery， Dell Latitude D820 batterycrispy edge, the surface is damaged, but you can cut, but also a lot of cheese which is good.

"But if you crumble the cheese into small pieces, so you have to destroy all of the cheese, because the larger part of the cheese surface."

The rapid degradation of the catalyst, the duration of the fuel cell is not long, and the U.S. Department of Energy believes that fuel cells will operate 5,000 hours, about 7 months of continuous use, practical solutions to energy vehicles.

Morgan and Holby, and the Massachusetts Institute of Technology Professor Yang Shao-Horn of Africa, the collaboration, we have found a workable solution to the rapid deterioration of the problem: When it comes to the catalyst particles, sometimes smaller is not better.

Their modeling is performed by 3M Corporation and the U.S. Department of Energy-funded shows that if a catalyst particle size, platinum and an increase of 4 or 5 nanometers, about 20 atoms in diameter degradation levels, significantly reduced. This  Dell Latitude D830 battery，Dell Latitude X1 battery，Dell XPS M1210 batterymeans that the catalyst and the entire fuel cell can continue to operate much longer if the particle size is two or three nano.

Fundamental physics research in particle size will expand its research scientists to explore a useful platinum, platinum alloy, which can reduce the platinum catalyst for fuel cell for consumption. Morgan is currently the research model to study the size of the stability of platinum alloy effects, such as copper and cobalt, platinum, platinum catalyst.

"Fuel cells are one of many energy technologies - solar power, batteries, etc. has great potential - to reduce our oil dependence and carbon dioxide emissions," said Morgan. "Computer simulation to learn about the development of energy technologies at the core of these new materials, a powerful tool."
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Friday 13 november 2009 5 13 /11 /Nov /2009 04:59

the long and difficult road of China vehicles

"China is already the world's largest auto producer and consumer countries, but now facing new energy revolution, vehicle power is China's auto industry battery chargera rare historical opportunity." The State Council Development Research Center of Chen Qingtai on November 12 China Europe International Business School held The "2009 Seventh China Automotive Industry Forum," said.

Car prices overseas M & A is then

The domestic automobile enterprises in 2008 and 2009 for two years developing in full swing. As of July 2009, China's domestic brand car products in the market share has climbed to 29%. Last month, China's auto production and sales exceeded 10 million, China's auto market from the number is already more than the United States.

China Europe International Business School Operations Management professor Thomas E. Callarman said: "The current economic environment of China's Overseas M & A a good opportunity." He pointed out that the Chinese automobile enterprises can directly go to the U.S. mergers and acquisitions.

"On one hand China is gradually becoming the most important global car market, its success is based on a joint venture between the Chinese government policies and local market conditions; the other hand, China's auto companies are gradually entering apple A1012 battery， apple A1022 battery，apple A1060 battery， apple A1061 battery， apple A1078 battery a foreign market, but want to be successful in foreign markets on the need for planning and skilled implementation, success will be presented in the next few years. "China Europe International Business School marketing professor Fu Wode said.

The Road Ahead is not good to go

However, despite China's auto industry, production, sales surge, but the domestic auto companies has shown a sharp decline in net profit. This shows that the cost of space for local businesses are close to the critical point, then the future of China's auto industry really optimistic?

Chen Qingtai introduction, Obama took on a clearly stated the U.S. auto industry's technical direction is plug-in electric vehicles, followed by major automobile-producing countries governments have introduced policies to support a new generation of batteries and electric vehicle development.

"And the major car-producing countries and large multinational corporations intensive industrialization, the Chinese electric vehicle industry, to form a greater contrast." Chen Qingtai said that although the Chinese government planned to form a 2011-year 500,000 e http://www.topbattery.net/ vehicles capacity. But this encouraging planning and did not change the major automobile companies for new energy vehicles to wait and see.

The Chen Qingtai of Chinese automobile enterprises have all kinds of defects is more blunt. "National 4 ministries put forward and promote the implementation of new energy vehicles in 10 city 1000 project, many cities are in a warm and fight, but some auto companies would only use it as a government special orders and display their own chance. And increase the electric car the formation of independent R & D and industrial capacity, almost no substantive ties. "Chen Qingtai said" Some car makers in order to win government subsidies, not to intensify R & D intellectual property but rather pre-empt the purchase of the accumulation of foreign key components of batteries and battery systems assembly, to meet the Government's immediate needs. "

Sustainable development must rely on the government

In this economic crisis, which almost all countries have taken concerted action, that is the automobile industry to support the planning. The Chinese auto industry's future sustainable development, and also to a large extent dependent on government support.

Chen Qingtai pointed out that in 2008 China's dependence on imported oil surged to 55.4%, becoming the world's second largest oil importer, dependent on the cost of oil will be greatly increased, the situation in latecomer countries is even grimmer.

However, Chen Qingtai believe that China-based electric vehicle power-oriented study of the layout of the new energy vehicles, has gone to the world the same starting line. "China's auto industry in the development of new sustainable energy development, also have favorable conditions, the first Chinese auto enterprise funds generally well-off, the ability to increase technical input;  apple iBook G4 12 inch battery， apple iBook G4 14 inch battery， apple MacBook 13 inch battery， apple MacBook Pro 15 inch batteryfollowed by China is the driving force required for the electrification of lithium, rare earth more countries; China's auto consumption in the last growth period, there is a clear market advantage. "

It is understood that the U.S. government to promote plug-in electric car plan, within a few months, the federal Act as a guide, covering both the management and motivation of the policy system.

"In recent years, China's relevant government departments launched a number of policy, research and development pre-played a positive role. But the existing policies are inadequate to support the industrialization of a substantial advance, according to China's national conditions, development of electric cars a package of plans and measures should be rose to national strategies, there should be the top-level policy design and sufficient intensity. "Chen Qingtai, said," The package plan should include the country's future automotive energy strategy, strategic positioning of the development of electric vehicles, electric vehicle industry, the path, related parts, materials, the development of services and related industries, power supply, charging infrastructure and so on. "

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Wednesday 11 november 2009 3 11 /11 /Nov /2009 03:40

Business is still in transition

Three quarters by 2009, company achieved operating income of 272 million, down 41%; operating profit loss of 1.23 million yuan, down 93%; attributable net profit  battery for laptopof 1.47 million owners of its parent company, down 88%; earnings per share 0.0085 yuan. 3rd quarter, the company achieved operating income 1 billion yuan, down 34.8%; operating profit of 540,000 yuan, down 90%; attributable net profit of parent company, owner of the 550,000 yuan, down 83%; earnings per share of 0.0032 yuan. 

     A substantial reduction in operating income year by the Department of macroeconomic fluctuations, subsidiaries of overseas companies and the Electrical and plate sharp drop in corporate earnings decline year on year. At present education and services and precision manufacturing operations in the second quarter of the overall situation has significantly improved to achieve a rebound, while the new digital TV operations and to expand solar business is still in the investment period. 

     A wholly-owned company set up wireless terrestrial digital TV operators will be across the country specializing in "Shenzhou every family pass" wireless terrestrial digital TV platform, full-service investment, construction and operations. Company with the provincial or city-level cooperation in the establishment of the main radio and television terrestrial digital TV operating joint venture, joint ventures, development of the wireless terrestrial digital TV operations. In October 2008, the company Dell Inspiron E1705 battery，Dell Latitude D410 battery， Dell Latitude D500 battery， Dell Latitude D505 batteryreplenishment Shanghai high-definition, and in cooperation with the Shanghai high-definition digital TV operations to speed up the wireless terrestrial digital TV industry fields. Digital TV business development situation is more satisfactory, is now officially signed two prefecture-level cities, and other cities under active negotiation. 

     Shares of a subsidiary of Shanghai Jiaotong University Yasuharu Green Energy is currently one of the major solar cell manufacturers in 2008 lead to great losses, the current international market demand, some recovery in the near future, the company has a pipeline network for infrastructure construction of the Italian state-owned enterprises signed to provide 2 megawatts of solar cell components, contract and agreement as a further successful co-operation provided by the National Chiao Tung University Yasuharu 2 megawatts of solar cell components. Present Topsolar over 95% of all orders for the international market orders, orders mainly from European countries. In addition Topsolar are bidding in cooperation with the Shanghai World Expo in Shanghai power plant photovoltaic demonstration projects. In the fourth quarter is expected to Topsolar will be able to a small surplus, to realize an annual sales income of 600 million yuan. 

     As the company's main stage of http://www.dell-laptop-battery.org/transformation, business development success with a large uncertainty, we do not have the company's earnings estimates and rating.
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Saturday 7 november 2009 6 07 /11 /Nov /2009 02:59

ipod battery and charging

Apple iPhone mobile phone battery life 675 days Thu, 26 Jul 2007 00:40:45 +0800 Apple iPhone mobile phone really is a lot of recent news, PC MAG and battery for laptopeven studied in depth look at Apple's iPhone battery life issues. In their view, the best of circumstances, iPhone's battery can only be used 675 days.

This data is probably derived from this kind. According to Apple's official documentation shows, iPhone cell phone's battery charge and discharge in full after 400 times the total electricity consumption can reach 80%. Through user feedback, iPhone need an average of 30 hours to recharge, PC Mag accurate measure of the result is 34 hours (that is, estimating an average of 1.5 days for the charge once). The Apple iPhone is fully charged time is 4 hours. In accordance with the best-case estimate, the same time charge the battery after each charge is also included in the calculation of loss if the battery life is 675 days.

PC Mag even in the release of the online computer program to enter your date of purchase of Apple's iPhone mobile phone will be able to arrive at the date of the need to replace batteries
Some guests have already released the iPhone, extending battery life approach.
1. Upgrade to the latest software, the latest update will allow iPhone even more power.
2. Fully charge and discharge at least once a month, your iPhone, which would allow the battery to keep in top condition.
3. When you do not use the iPhone, when I remember locking the screen.
4. Off when not in the  IBM ThinkPad R52 battery， IBM ThinkPad T40 battery， IBM ThinkPad T41 batterybest wireless and Bluetooth.
5. Open the automatic brightness adjustment, this feature can help save power.
6. Close the music player's equalizer settings. Can help to save power.



ipod battery and charging a basic knowledge
ipod battery and charging the basic common sense, to correct some errors in

1. Ipod battery is lithium, lithium batteries and nickel-zinc batteries before the contrary, lithium no memory effect, are most afraid of is the complete discharge of the battery .. This will result in premature aging ~ `


2. Li-ion battery inside the automatic protection circuit, full power, the will automatically cut off the lines, but to be safe, do not plug in the charger and forget to take down ...


3. Ipod automatic battery conditioning, when the power is too low, it will automatically shut down, pay attention, this time of the ipod battery still has power, without the use of cases, about 3-5 days will be completely put end ... so , when the ipod battery is too low, or automatic shutdown prompted, we must remember that charge; to avoid the complete discharge, cause damage to the battery!


4. Ipod battery is fully  IBM ThinkPad T42 battery，IBM ThinkPad T43 battery，IBM ThinkPad T60 batterycharged or partially charged can not affect the battery life (and the former nickel-zinc battery is completely different Oh, do not stick to the old idea of charging oh ~ ~), as long as your convenience, you can always be lithium-ion battery;


5. Batteries consumables, do not use will gradually reduce the maximum electricity consumption; So, as much as possible to enjoy your ipod bar, is rarely used and will not be extended too much battery life;

6. Charging the battery usually 1-2 hours, both filled with 80% of electricity, and then after 2-3 hours, can all be filled;

7. Ipod are generally two kinds of 5V and 11V charging voltage, the owner is aware of 5V circumstances, photo charge will create problems, the other seemed to be all OK;

8. The battery long-term use,  http://www.digital-battery.net/he power will be less this time you need to replace the new battery had; battery life is generally 1-2 years, when the battery can not be used, you can contact Apple to replace the battery, or the purchase of non-original of the batteries, their replacement)

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