First: Some tricks to help rechargeable battery life extension of several years

1. Do not waste charging cycles

Each battery has a specific life, usually referred to as the charge cycle or battery cycle. In short, the battery has a specific number of charge - discharge cycle, beyond the limit it is no longer suitable for use.

Some hardware manufacturers will release cycle numbers, others will not. For example, Apple said its iPhone battery to complete the 500 charge - discharge cycle, the charge will be reduced to 80% of the original battery. While the MacBook Pro or MacBook Air after the completion of 1000 cycles, the amount of charge will be reduced to 80%.

Some people think that they can avoid the charge-discharge cycle by periodically charging the battery so that the battery always remains in the non-fully discharged state. Unfortunately, you can not change the physical rules.

If you only let the battery discharge 25%, then 4 times will be completed a cycle. If you discharge 20%, you need to complete a cycle 5 times.

All you have to do is prevent wasteful cycles and make sure the equipment is charging when necessary. However, do not always charge the battery, it will lead to overheating of the battery, this approach itself is harmful to the battery, such as when the battery use in solar powered portable generator.

In other words, do not let the battery go through an unnecessary charge-discharge cycle. But I mean, do not always keep the device in a charged state, which is also harmful to the battery. Because the battery needs to regularly discharge, in order to maintain the internal chemical substances remain in good condition.

Just need to pay attention, do not waste charge - discharge cycle.

Lithium Battery Pack BMS Product’s the Third Architecture

Currently lithium battery BMS products are mainly two kinds of architecture, centralized management system and distributed management system. Centralized have lower cost, but the wiring harness is more complex, and the need for a single cell to corresponding, if the wrong battery will be short-circuit the risk of fire.

Distributed wiring harness is relatively simple, but the monomer management unit (CSC) still need to maintain a one-to-one correspondence with the battery cell (by setting a soft address or hard address on the CSC to solve), it let the production and maintenance of an additional workload. Another point to note is that if the active balancing function is to be implemented, the BMSs of the two architectures will require additional wiring to complete the energy transfer. Moreover, another problem to be solved is the switch matrix, which is how the energy flows into the cell from the entire cell.

There are currently used in the program is through the relay, to achieve a simple, but also brought the issue of life and reliability. Because the relay is a mechanical electronic components, there are life-time restrictions and the risk of adhesion during switching. Another solution is the use of electronic switches, MOSFET, but will bring the cost and complexity of the circuit rise.

From the functional realization point of view, BMS all functions are not insurmountable technical threshold, but from the practical point of view, BMS product is difficult to complex wiring harness, one-to-one relationship and high current active low balance cost realization. Centralized management systems and distributed management systems are not a good solution to these problems.

There is a company has proposed a third architecture, modular architecture, clean and agile to solve the BMS problem.

The system consists of UM (single module), controller and bus (2-wire system) three parts. The battery pack is divided into one or more groups according to the number of cells. Each cell is equipped with a UM module, which is a standard module, without any hard and soft address setting. The module is 4 ports, 2 inputs 2 outputs, the input is connected with positive and negative pole of the battery cell, the output is connected with each bus line; The bus line is 2-wire system, can transmit data and energy, active equilibrium current can reach 10A; Controller connection, thus forming a system. Like building blocks, multiple systems can be connected via CAN bus to build a larger (100 series level) of the battery energy management system, building modular architecture hence the name. The modules and buses that make up the system are standard components, and only the controller is set up according to the size of the system.

At first glance, this architecture is similar to a distributed architecture in that its UM and distributed 

CSC functions are similar; however, their UM is simpler and more flexible than the CSC without any

 address setting, that is, any 2 UM can replace each other, production and maintenance efficiency will be much higher, the operator requirements are not so high. Bus only two lines, yet the data transmission and energy transfer unify, solve the wiring harness and matrix switch problems. This third BMS architecture has the potential to become the ultimate BMS product architecture.

Several functions of Battery BMS

(1) Accurate estimation of SOC:

Accurate estimation of the state of charge (SOC) of the power battery, that is the remaining battery power, to ensure that the SOC is maintained within a reasonable range to prevent over-charging or over-discharging damage to the battery and display the remaining power of energy storage battery. The state of charge of an energy storage battery.

(2) dynamic monitoring:

In the battery charge and discharge process, real-time collection of batteries in each battery terminal voltage and temperature, charge and discharge current and the total voltage of the battery pack, to prevent the battery overcharge or over discharge phenomenon. At the same time can give the battery condition in time, pick out the question battery , to maintain the reliability and efficiency of the entire battery operation, so that the realization of residual power estimation model possible. In addition, the use of historical records of each battery, but also for the further optimization and development of new electric, charger, motor and other information to provide a basis for offline analysis of system failure.

The battery charge and discharge process will usually use more accurate and more stable current sensor for real-time detection, the general current according to the BMS front-end current of different sizes, to select the appropriate sensor range for close to 400A, Open-loop principle, domestic and foreign manufacturers are able to bear low temperature, high temperature, strong earthquake JCE400-ASS current sensor, select the sensor need to meet the high precision, fast response time.

(3) the balance between the battery:

That is single battery balanced charge, so that the battery pack in all the batteries have reached a state of equilibrium. Equilibrium technology is currently the world is committed to research and development of a battery energy management system of key technologies.

Faraday and LG Signed 2.4 Billion Battery Orders

According to foreign media Electrek reported that Faraday future company (Faraday Future) and South Korea's LG Chemical signed a battery supply agreement for electric vehicles. The deal was valued at $ 2.24 billion. If the value per kilowatt-hour battery 145 US dollars, the order can meet the battery needs of hundreds of thousands of cars. Our lifepo4 battery pack is composed of battery.

The plan has been a mystery since Faraday's announcement of electric car production a year ago. The company's leadership problem has been confusing, until recently it was reported that China's LeSee company and its founder Jia Yue-ting to establish a relationship.

According to the Herald Herald, it is puzzling that Faraday's next big battery contract is for the LeSee supercar. From the size of the document, if the battery is not all for the LeSee syper car in China, the company will achieve greater production targets. The battery also could be used in solar powered portable generator.

Earlier this year, Faraday in the United States Nevada future to spend one billion US dollars (about 6.67 billion yuan) of the factory groundbreaking. Its first production models of spy photos also repeatedly exposed, from the appearance point of view is a cross-border car.

China donates photovoltaic lighting equipment to Equatorial Guinea

The Chinese Embassy donated photovoltaic lighting equipment to the Chiyu Youth Foundation in Equatorial Guinea on the 29th. Ambassador Zhao Hongsheng and Chiyu Youth Foundation, the representative of the Chinese Embassy in Chekiang, attended the donation ceremony.

The Chinese embassy donated a total of 150 sets of photovoltaic lighting equipment. The Chiyu Youth Foundation will make available all equipment to the inhabitants of the town of Etonisonne, Velientz.

Dolores expressed his heartfelt thanks to the Chinese Embassy at the ceremony. She said that the rural residents of Guinea will be used to China's green lighting, which is conducive to the sustainable development model in the rural areas of the promotion and popularization. Use green energy, use solar powered portable generator.

It is understood that this will be the first batch of photovoltaic lighting equipment into the red population of several families. Ambassador Zhao Hongsheng said: China and Chekki are good friends and good brothers. China sincerely hopes that the people of Chekiang will live a better life. These lighting equipment will allow pollution-free, sustainable light illuminate the lives of the people of red several people, so that they actually feel friendly of Guinea.

Guangzhou new energy vehicle production increase two times from January to July

August 30, the Guangzhou Municipal Bureau of Statistics official website released data that the city's smooth economic operation from January to July, the main economic indicators have fluctuated, the overall stability. Among them, industry, consumption growth was flat in the first half year, investment growth slowed slightly. Guangzhou to implement the structural reform of the supply side has gradually markedly, new energy, a new generation of information technology, new materials, product output to maintain growth doubled, driven by corporate profits were recovering faster growth. The new energy can be used in solar powered portable generator.

High value-added new products to increase the rapid growth of corporate profits

January to July, Guangzhou to achieve above-scale industrial output value of 1.087773 trillion yuan, above-scale industrial added value of 269.214 billion yuan, up 6.8% year on year growth rate was flat with the first half.

The gross output value of the three pillar industries increased by 8.9%, and the growth rate was 0.4 percentage point higher than that of the first half year. Among them, the automobile manufacturing industry grew by 11.6%, the electronic products manufacturing industry increased by 11.8% and the petrochemical industry increased by 1.7%. The latter two grew faster than the first half year.

Among them, the three pillar industries of new products momentum is good. The new products of automobiles maintained a rapid growth. The output of new energy vehicles and sport utility vehicles (SUVs) reached 2,352 units and 568,100 units respectively, up by 2 times and 79.2% respectively. In the new information technology products, Devices, fiber optic cable production increased by 2.2 times and 33.4%; new materials, lithium-ion battery products were doubling the growth trend, the output growth of 1.2 times.

High value-added new products to increase, as stimulating industrial enterprises profit recovery was one of the reasons for the rapid growth. The first half of this year, industrial enterprises above designated size realized total profit of 53.922 billion yuan, an increase of 16.4%, but the growth rate from January to May fell 4.1 percentage points. According to previous public figures show that in the first half, new energy vehicles, optoelectronic devices, lithium-ion battery production respectively achieved year-on-year growth of 3.9 times, 2.6 times, 1.3 times, it include LiFePo4 battery pack.

Fixed asset investment growth rate of 12.7%

Investment in fixed assets, the total investment amounted to 492.227 billion yuan, the overall growth rate of 12.7%. Since the first half of this year, industrial investment has been rising since the decline, its growth rate continues to accelerate, an increase of 15.4%, the growth rate of 2.7 percentage points higher than the city's investment. In investment in services, investment in industries related to producer services and cultural life increased rapidly. Investment in leasing and business services, education, culture, sports and entertainment increased by 2.0 times, 1.1 times and 18.8% respectively.

January to July, the city's total retail sales of social consumer goods 492.227 billion yuan, an increase of 8.4%, growth was flat. At the same time, consumer prices (CPI) rose 2.6% year on year, PPI fell 2.5%, and purchase prices fell 4.6% year-on-year.

The retail sales of daily necessities, cosmetics, Chinese and Western medicines and gold and silver jewelry increased by 25.0%, 24.7%, 15.3% and 12.2% respectively over the same period of last year, which was in line with the improvement in the quality of consumption and quality improvement of residents. Accounting for nearly 30% of the above-mentioned auto retail sales growth of 6.4% in the first half growth rate of 5.9%.

In terms of import and export trade, the value of imports and exports of goods in Guangzhou from January to July was 463.348 billion yuan, a decrease of 1.1 percent, a decline of less than 3.0 percent of the national and 1.3 percent of the province. Specifically, the export growth rate down, imports fell to expand. However, Guangzhou's cargo throughput, airport cargo throughput, airport passenger throughput, port container throughput growth rate has expanded.

From January to July, the growth rate of revenue and expenditure and the growth rate of total tax revenue all have some callback. Among them, the "battalion change" the full implementation of the impact, which accounted for over 60% of the national tax revenue growth of 5.4%, the growth rate than the first half increased 2.2 percentage points; land tax revenue growth of 5.7% growth rate down 8.1 percentage points.

At the end of July, the deposit balance of local and foreign banks in the banking sector in Guangzhou was 4.52 trillion yuan, up 1.9 percent; the loan balance was 878.562 billion yuan, up 7.4 percent, down 5.3 percentage points and 1.8 percentage points respectively.

Cycle process during the charge and discharge system

Lithium-ion batteries use process is the process of charge and discharge cycles, the magnitude of charge and discharge current, charge and discharge cut-off voltage selection and use of charge and discharge methods such as charging and discharging system of lithium-ion battery cycle life is also very important. It is usually used in solar powered portable generator. Where blindly increase the battery operating current, increase the charge cut-off voltage, reduce the discharge cut-off voltage and so will decrease the battery performance.

Different electrochemical systems of lithium-ion battery charge and discharge cut-off voltage is different. In the lithium-ion battery charging process, where more than the charge cut-off voltage that occurred overcharge.

K.Maher and other LiCoO2 battery charge cut-off voltage in turn from 4.2V set to 4.9V, and the experimental electrode materials were X-ray diffraction and Raman spectroscopy experiments showed that the graphite anode and lithium cobalt oxide anode were structural changes. By testing the different cut-off voltage of the electrode after charging different SOC entropy curve, also found that the electrode material structural changes occurred.

Lithium-ion battery overcharge, from the cathode out of the excess lithium ions will be deposited or embedded in the negative electrode, the active lithium easily with the solvent reaction, the release of heat so that the battery temperature. Positive decomposition of oxygen generated by the decomposition of the electrolyte easily and produce a lot of heat.

When the discharge voltage of the lithium battery is lower than the discharge cut-off voltage, overdischarge is formed. In the process of over-discharge, the lithium-ion from the negative pole will be excessive prolapse, the next re-embedded when the charging will be more difficult. YU Zhong-Bao and so on to the MCMB as the cathode, LiCoO2 positive for the battery over-discharge to 0V, the copper collector fluid was more serious corrosion, negative SEI film was damaged, re-formed SEI film performance is poor, the negative resistance increases, polarization enhancement. The battery discharge capacity in the cycle after the discharge, the charge and discharge efficiency is greatly reduced.

Li Yan were studied 18650 lithium-ion battery discharge at different magnification. The results show that the LifePo4 battery pack capacity decay increases almost proportionally with the increase of charge / discharge ratio. High-rate cycle of LiCoO2 / graphite lithium-ion battery capacity of a serious decline.

The main reason for the serious attenuation of the capacity is the change of the structure of the cathode material and the thickening of the negative electrode surface film, which leads to the decrease of Li + and the obstruction of the diffusion channel. In the case of large current discharge, the need for rapid ion implantation, out of the positive and negative, the reaction is very fast.

Tang Zhiyuan and so on through the experimental analysis that: because the battery discharge in large current needs in a short period of time to release a large capacity, rapid and violent electrode reaction, some lithium ions too late to de-embedded or through the anode material discharge process has ended . In addition, the battery tabs may fuse under heavy current conditions and equipment components may be damaged.

Through analysis we can see, both in the design and manufacture or use of the process, the impact of lithium-ion battery cycle life of many factors. Lithium-ion battery applications more and more widely, for example used in portable solar power generator, the demand for lithium batteries in the quantity and quality are put forward higher requirements. Cycle life of lithium-ion batteries directly affect the use of time and quality, so producers of its influencing factors of the study is very necessary. Only in the development and production process will affect the cycle life of all factors are well grasped, enterprises can in the fierce competition in the market take the initiative. Consumers should pay attention to the use of lithium-ion battery characteristics, according to the instructions prompt use of batteries.