Digital battery

According to the report of the research firm market lithium-ion rechargeable battery shipments worldwide have continued to increase in 2007 lithium-ion rechargeable battery compared to world supply in 2006 increased by 17% because lithium-ion batteries in energy density advantage of using lithium-ion batteries can reduce system complexity and cost of system integration.

 

Lithium-ion rechargeable battery characteristics with the load / discharge the requirements of

Lithium-ion rechargeable battery with a single high voltage, small size, light weight, energy density, long cycle life, self-discharge current is small, no memory effect and no environmental pollution, good prices and benefits of weight. And the lithium-ion battery curve of discharge is very flat, so you can drain the battery within a period of stability in the whole power is ideal for small portable power power.

 

Series of lithium-ion battery voltage is usually 3.0 ~ 4.2V. When the battery is discharged, the voltage is subsequently begun to decline, the output voltage can change dynamically with the load changing. Table 1 shows the lithium-ion batteries on other features.

 

Lithium battery ion / lithium-ion batteries discharge need to monitor the voltage on the one hand to avoid overloading the other hand, to prevent excessive discharge. Would charge lithium-ion battery / control discharge testing of Dell Inspiron 1526 battery capacity and charge / discharge anomalies occur in the process to ensure protection.

 

When a number of series lithium-battery ions / use of landfill series after differences in the characteristics of lithium-ion batteries large lithium-ion battery, there was the specific charge or increase the probability an excessive discharge. Therefore, discharge of lithium-ion battery, the need to use a special discharge circuit when a battery voltage of lithium-ion battery discharge drops, until the following limit can automatically cut the discharge circuit , does not discharge lithium-ion battery appears to decrease their useful life. In addition, lithium-ion battery when charging lithium-ion battery should pay attention to time and changes in lithium battery temperature ion, so it will not be accountable for ensuring that battery life of lithium-ion battery. If the battery is over-load, it will accelerate the aging, but also the loss of energy it can transmit the system. Therefore, multi-cell lithium-battery ion / discharge circuit to take into account more problems than single-cell lithium battery ion / discharge circuit to consider the issues more.

 

Stored for a long period has been discharged lithium-ion batteries may be in a state of deep discharge (each set of lithium-battery voltage ion is generally less than 3V). In this case, for a full lithium-ion Dell Inspiron 5100 battery charging process to be completed some time before the trickle charge.

 

A larger load current can not make time for lithium-ion battery charge too. A voltage greater load current can be rapidly achieved peak, but the float take some time. Typically, the float is twice the initial charging time.

 

Rechargeable lithium-ion battery with the first constant charging current, then a constant voltage means, first of 1C or less constant load current until the battery voltage reaches the voltage limit load. Value of constant voltage is generally between 4.1 ~ 4.2V, precision constant voltage to be controlled to ± 1% or less, depending on the lithium-ion battery manufacturers, and lithium-material ion battery anode.

 

A typical lithium-ion battery charging characteristic curve in Figure 1. In the constant voltage phase, lithium battery ion current decreases. The voltage reaches the threshold voltage and load current to 0.03C (nearly 3% CI), the charging process is usually at the end. Most lithium-ion Dell Inspiron 5150 battery charger full power for about 3 hours. As lithium-ion batteries self-discharge rate is relatively low, so generally no need to run the current process of pricing.

 

Rechargeable lithium-ion battery to provide voltage regulation to correct a problem in addition to the two ends of the battery charging voltage is not exactly equivalent to be added to each battery voltage section. Unlike the battery in the various components of the voltage drop I × R caused. These factors include termination resistors in May, the protection of MOSFET on resistance, internal connections and detect resistance (for example, used to measure the capacitance of the battery).

 

Solution to this problem is in the lithium-ion battery voltage constant phase compensation of dynamic tension. “Dynamic” refers to the charge that I run, diminishes the value of compensation I × R, but also with the decrease. For example, TI bq2057 Charge Management IC has the function of automatic compensation.

There are three main methods currently used to determine the state of battery charge: measuring voltage, resistance power calculation and measurement.

 

The method of computing power is more complicated. The measure of power to be able to constantly monitor the Dell Inspiron 6000 battery voltage, current and temperature. Then, as the discharge rate, aging and temperature to adjust capacity, and was followed by a state of battery discharge, the remaining power, the battery can also use the time.

 

The main source of errors in power calculation due to cellular aging, self-discharge, and product differentiation between manufacturers, resulting in changes of the impedance of the battery. In addition, power calculations to measure the electricity consumption would only power the full power to run completely out of time to update the discharge capacity of the battery, and users do not often the battery has been fully developed electric shock.

 

Power measurement method using the impedance voltage based approach to determine the onset of the condition of battery and lack of capacity. Then they charge in a case of using a long-term approach by adjusting the remaining capacity of the battery and the beginning of the state. They are in every cycle depending on the voltage and current information updated calculation of the impedance of the Dell Inspiron 6400 battery. Finally, based on open circuit voltage and impedance information, calculate the average load in the remaining time available for a discharge curve.

 

IT in the “Impedance Track” The technology is based on the introduction of chip barometer bq20z80. A claimed that the use of the battery throughout the process, the accuracy of calculating the power of lithium battery is left at 99%. The chip barometer with an SMBus interface to the battery capacity of the information transmitted to host controller system. Host Controller remaining power management battery to extend the use of the system time.

 

Smart Battery

Present Dell Inspiron 700m battery rechargeable / discharge management, extensive use of a variety of practices and MCU / CPU for data exchange, processing a variety of bus technologies, for example, few buses (BITBUS ), System Management Bus (SMBus), IC exchange of data between bus (I2C), Universal Serial Bus (USB) and a simple peripheral bus (SPI) and so on.

 

In laptops, the use of bus technology may be state of the battery, the battery can be used time and energy remaining battery, batteries, parameters such as the battery if it is normal for the management and inspection, and make the battery status data shows that when the battery is exhausted, the computer may turn off automatically to save the data. Similarly, in the current widely used mobile phone these technologies have also been widely used, greatly facilitate the users use.

 

Someone under the smart battery is defined as follows: drums + electronics + control bus = Smart Battery. Smart Battery, SMBus, and “smart Dell Inspiron 8500 battery charger, the three formed a Smart Battery System (SBS).

 

The multi-cell lithium-ion battery charge / control of protection against discharge IC

Lithium-ion rechargeable batteries due to a series of advantages and it has become increasingly broad range of applications in the world large companies integrated circuit fabrication (such as Ti, Maxim, Linear, National, and Intersil Corporation, etc.) have launched a number of models of multi-cell lithium-ion rechargeable battery management integrated circuits. These products with different features, excellent performance, each section can be responsible for lithium-ion battery / discharge conditions and charge / discharge temperature detection and protection. Among them, some use 8-bit MCU core and the charge of lithium-ion battery / unload work of the state register of lithium battery ion / discharge the work of the host state and analyze and judge, to ensure that each lithium-ion battery is fully charged, and extend its life.

 

TI introduces bq2150H lithium-battery ion / discharge detection and protection control IC, which can be used for 2 to 5 series Li-battery ion / discharge applications, can be used alone, and may take five load / unload work LED display.

 

TI introduced the UCC3957 is used for 3 / 4 charge Li-ion Dell Inspiron 8600 battery / cons discharge protection of integrated circuits, through the state’s internal mechanism can be achieved for each section of the battery over charge / discharge detect and protect lithium-ion battery over-discharge protection current. UCC3957 by external P-channel MOSFET control of the load carrying / protection against discharge, using two charge / discharge over-current protection functions of command. If the charge / discharge process of lithium-ion battery is not connected, the screening can be achieved through the control of appropriate protective UCC3957.

 

TI has introduced the series bq2941X lithium-ion battery charge control IC is used to protect 2/3/4 two lithium-order ion battery protection for a series of integrated circuits, the main characteristics is that they charge Surge Protection against voltage threshold is different Equipped with high precision on-detection circuit voltage and the on-time voltage detection circuit programmable delay. Pulse work load.

 

Linear Introduces Lithium-Ion Battery Charger IC control such as LTC4006/LTC4007/LTC4100, etc., for 2 ~ 4 Li-Ion Dell Inspiron 9200 battery charging, while the LTC4008 can be used for 2 to 6 Lithium-ion battery charging applications , the maximum load current is 4A, the maximum input voltage 28V, using switching control workload.

 

National Semiconductor has introduced the LM3420 series of lithium-command Ion battery charge IC can be used for 1 ~ 4 Li-battery charge control to ion charge Li-ion battery control, linear and switching applications circuit.

 

MAX1894/MAX1924 Maxim’s, etc. 3 / 4 Li-Ion battery charger IC can be obtained with the control of each cell lithium-battery ion / discharge voltage detection to prevent lithium-ion battery over load / under charging, effectively extends the lithium-ion battery life. With due to charge / discharge the battery and short circuit box caused by the charge / discharge is not normal protection and trickle charge current control can be used to control the release of deep charge battery safety Automatic. MAX1894X for four sets of rechargeable lithium-ion battery applications, protect the threshold hysteresis, while MAX1924V and / MAX1924X can be used for 3 / 4 series Li-ion Dell Inspiron 9300 battery charger at the threshold of protection has hysteresis. MAX1894/MAX1924 have two logic-input signal level, the use of these two logic input signal level by the MCU to complete the process of lithium-controls shutdown of ion battery.

 

Maxim has introduced the MAX1870 is another circuit smart battery management integrated charge that can be Use 2 to 4 Li-control applications of ion battery charge, the integrated user-programmable 8-bit RISC-based micro - controller, data multi-channel Get channel cell, high-speed SPI interface circuit, master / slave SMBus interface circuit that allows the detection of lithium-ion battery. The use of multiple MAX1870 is string data acquisition circuit unit can be detected in the accuracy of 50mV in voltage lithium-ion battery, and using multiple channel data acquisition unit circuit of the MAX1870 to detect temperature inside and outside, easy to use.

 

Another example Intersil has introduced the ISL6251 ~ ISL6257, ISL6258 and ISL88731 (using SMBus) and other lithium-ion battery management ICs load control can be used for 2 to 4 Li-management applications Ion battery.

 

Intersil has introduced the ISL9208 can be used for a maximum of seven lithium-load management ion Dell Inspiron 9400 battery and control circuit with a load inside and outside the functions of detecting temperature protection control. In the ISL9208 has an internal embedded MCU cores, using the MCU core can complete the charging of lithium-order ion battery management. 4 ~ 7 series rechargeable lithium-battery voltage ion charge up to 30V through the MCU core, detection and control can be obtained for each cell lithium-battery ion / discharge detection power and control, ensuring the charge / discharge lithium-ion battery voltage balance and the battery life of lithium-ion battery. And the ISL9208 supports a multi-cell lithium-ion battery charging applications in parallel, the use of flexible and practical.

 

Summary

Use lithium-ion battery is growing, while lithium ion Laptop battery charge / discharge management has also become a very important and reasonable to charge lithium-ion battery / discharge of lithium-life ion battery and the use of safety are of great importance. And multi-cell lithium-battery ion / discharge and there is a continuous flat load / discharge, adequate electricity and not to discharge problem, to solve these problems, is inseparable from lithium-charge of ion battery management / discharge, because the rich control IC function, using lithium-IC battery ion / management of discharge is a good solution.

1, high-profit event

 

U.S. First Solar’s gross margins above 50%, but such a high gross margin because the company has a core of cadmium telluride thin film technology and its equipment are mostly self-designed, proprietary technology, so their cost than most solar companies is much lower. From the breakdown of costs can be verified that, although First Solar equipment depreciation for 5 years, compared with the other producers have AMAT Applied Materials, Inc. 7 years shorter, but still higher than the depreciation expense of the unity of the amorphous silicon plant AMAT more than 20% lower than the AMAT of the laminated product is 40% or more. First Solar thin-film producers all over the world, a good benchmark, but it’s amazing the goal is not easily available, and the general activities des

 

2, technical risk concerns

 

Due to rapid technological progress, the average price of polysilicon components from the current level of $ 4 / W by 2012, two U.S. dollars / W; thin-film batteries from the current $ 2 / W to $ 1 / W, the thin-film makes solar production capacity could reach 20% of the total solar energy, is now only 7.6%. Thin-film solar sony VGP-BPS2A battery technology must be improved, for example, need to improve the existing microcrystalline silicon coating because the thickness of the microcrystalline silicon solar impact performance. Thin-film solar batteries to do is thin, the conversion rate to improve a significant reduction in thickness to reduce production costs and other metrics. Most of the province of silicon thin-film battery is using a special process that continued gas with silicon deposited on glass carriers can form a layer of paved with nano-scale particles of silicon film as a piece of glass, with an area of up to 1 square meter, or even a few square meters. The thin-film solar batteries in the same size on the weaker power generation capacity than conventional batteries, photoelectric efficiency of only about 6%. Chinese Academy of Sciences Guangzhou Institute of Energy, according to recent forecasts by the year 2015 this number will increase due to technical advances by 12% to 16%. The world’s most advanced ion-beam deposition of nano-crystalline silicon thin-film technology, China is still empty. Crystalline silicon batteries with very different production technology is widely in manufacturing thin-film battery, like the semiconductor industry, such as vacuum coating technology, key technology have used this level of mastery and advanced directly to the volume of products affected income, indirect impact on the profitability of the company. Thin-film battery industry is a technological innovation on the rapid development of industry is based has been built is to explore one of the best process route too, so the need for continued improvement from the technology point of view thin-film sony VGP-BPS2 battery factory, manufacturers of crystalline silicon solar batteries are producing more need for a strong R & D and technical team. From a technical originality, digest and absorb and re-raise three are usually standards, Chinese companies are only in the most important independent intellectual property rights of long term in a weak position. If you can not catch up, then the thin-film solar batteries has continued to migrate to the “Introduction, backwards, then the introduction of” passive follow the trend of the old road, not in a position to the chain from production to sales of high End-to-fill.

 

3, equipment and raw materials short board

 

Thin-film battery technology development is shorter forms, no common technology and common equipment, the latest large-format thin-film VGP-BPS9/S battery devices offers a turnkey project is primarily the United States, Applied Materials (AMAT), Switzerland, Oerlikon and Japan’s ULVAC 3rd Equipment depreciation is one of the major costs of thin-film batteries, according to the current stock market listing, with the capacity of the battery production line of thin-film silicon prices are 6-10 times, including glass (glass and other conductive glass), EVA, Target and Gas and other important raw material supply, the current international giants are monopolies, high prices and no supply. ITO thin-film batteries require a higher current strength of weak domestic manufacturers, the market especially from Japan, NSG and the U.S. AFG partition. With the outbreak of the domestic production of thin-film batteries to supply most likely the result of the main raw material. Target current domestic supply, which is dominated by large international companies, Heraeus, Germany is the world’s largest supplier on the domestic market share of more than 6 in. Moreover, there is no domestic production of silane, but mainly large international companies with limited expansion opportunities as demand for LCD and other high silane is coupled partial delivery is still in short supply, prices continue to rise to maintain a high level does not exclude the possibility silicon thin films face Queliao risk. In addition, the thin-film cadmium telluride (CdTe) materials, there are still concerns about the toxicity, environmental protection and recovery mechanisms, tellurium supply mechanism hidden dangers, copper-indium-selenium (CTS CIGS) materials, it is the question of indium prices.

 

4, the market risk

 

Everything that is divided into two halves, and look at problems of the market, there must be an objective analysis of dialectical materialism. The great development of the photovoltaic industry, leading to rising prices of key raw material silicon, and finally forced to alternatives to the downstream business, believe it promoted the rapid development of thin-film technology on a very large number of companies find that they have a Starfall, crystalline silicon solar technology found pregnancy dive with a great breakthrough in the pricing on the eve of a sharp. This result is still at the level of the small thin-film Dell Inspiron 8500 battery market and the strong momentum of development will be the impact of changes in market investors form must be fully understood, otherwise errors can occur.

 

5, risks of investing in

 

Currently, Chinese companies have much in the introduction of foreign monopoly, invested thin film solar battery production lines. Three giants of the world, one of the United States, Applied Materials, Inc. amorphous silicon thin film solar modules to produce a series of automatic production line, for instance, to project a total investment of 14 billion yuan, annual production of amorphous silicon thin film solar batteries 500MW, with an annual turnover of 20 billion yuan. Investment intensity per megawatt of production capacity by 2800 or 28 million yuan RMB per watt, a turnover of 40 million yuan to invest grid / MW, or 40 yuan / W. This easy-to tens of billions of investment risk should be carefully examined. Switzerland and Europe Likang automatic production line of thin-film hp PP2182L battery prices of imports of 100 million yuan dollar, combined 700 million yuan. In addition, the production process is environmental issues will consume a large amount of investment in environmental protection department or face opposition.

 

6, financial difficulties

 

Solar PV industry is a money-burning industries, the financing capability of a large company test. But the most dangerous place, but also risky places, is from a philosophical standpoint, the greater the risk, the greater the chances. In other words, there is no opportunity without risk. The wind is now that my votes. With minimal investment to earn the greatest profit, is the eternal view venture capitalists, but also the strategic goal of the philosopher, the two differ only pure venture capitalists will benefit as a goal. Investors on the financing side of the evaluation criteria are mainly two first the profitability of enterprises, followed by the scale. In addition, enterprise system, corporate culture, team composition, executives and others have an assessment. Standing at a higher level view of these questions, we will have time to go see the industry that has little relationship, because the key to see the VGP-BPS10 results. First come, the current environment, then there are other problems can not be generalized.

 

Our answers:

 

1. R & D and commercialization of solar PV companies should also focus on understanding the two. Accurate select the entry point to participate partially in control of the situation with the strategy, both in accordance with national conditions, also in line with the best economic option because the lowest price to produce the best results are always the best choice for investment. “Power wins very brave man to win power disparity wise man.” Achieve control of the situation, do so by local targets, the need for more intelligence to this, because it requires a global vision of a comprehensive strategy, intelligence and strategic courage. People who can not fearful strategy for winning the top spot because it is often the most dangerous, but also the balance of power in force. Big bet on solar PV by the “technology innovation and lower costs” that two keys so that the cost of solar power for the next generation of 0.5 yuan per kWh on the price and VGP-BPS9/B thermal energy equivalent to a strong competitive advantage to connect on the market to the premise of the initiative to regulate the use of large scale, when promoting the market demand burst like a blow-out type, solar batteries on board from the current use of additional alternative energy peak.

 

2. Although the same time, faced with a shortage of materials, technology development, leading talent and its own challenges, such as intellectual property rights very short, but we are committed to their own multi-level research and development team, construct addition, it should with Applied Materials to work as the United States, Japan, ULVAC, Switzerland, Oerlikon thin-film battery technology world, such as monopoly giants technology alliance, which is a good strategic decision.

 

3. Japan’s Sharp Corporation developed a prototype solar batteries on gallium arsenide ingots, has its photoelectric conversion rate reached 25-28.5%, according to the story of Sharp, an energy efficiency approaching 30% can have a prototype product, when the actual efficiency of production is very up to 20%. Who is the first to master the advanced technology, who reflects the lead in industrialization, the first to the photovoltaic industry, “high growth, high investment, high output” properties.

 

4. Production of photovoltaic power in China today is not simply the application of power, short-term needs the support of the international market, but the long-term strategic perspective, the domestic market is a strong resource can not be ignored. Together with the opening of the domestic solar PV market approaching footsteps, “staking their claims,” floating on the operation of the tactical turn table. Need as quickly as possible sunshine intensity of the former government signed a joint construction of three solar power plant demonstration project cooperation agreements for the construction and application of solar energy, local governments, or if the BATBL50L6 technologies and products ready to promote the market have been divided since a long time.