Wednesday, 26 October 2016

Several Reasons of Lithium Battery System Fires

Security is the lifeblood of child battery, the lifepo4 48v system from the inside out cause of the fire in recent thinking and analysis, this is considered a major reason for the layers to push forward, then consider the previous and future accidents put to match then the future of an accident PPM (parts per million) based on the actual design of each model speculation. Hereinafter all manufacturers names are removed, does not explore this topic for any enterprise, not judge.

It is assumed from a single problem, and then extended to the global dimension of the experiment, it can be seen:

Analysis of the whole system just to match the battery fire this extreme event occurs, we segment the contents from mechanical abuse, battery system design basis is to focus on in a relatively safe position of the vehicle, to prevent problems in the course of the vehicle the whole mechanical design of course is a lot to do experiments security content acupuncture, extrusion, etc., but in fact the problem caused by the mechanical abuse but easily become a problem.

In Tesla's two accidents as an example:

Lithium ion Battery Explosion

1. On fire in Smyrna, Tennessee, this car electric cars rushed to drop the road trailer hitch, the fire broke out after the collision chassis.

2. When the driver hit the turn, and through the wall of a cement eventually hit a tree and stopped the fire.

3. In Seattle, the owner called and hit a metal fragments, so he left the highway. After the failure of the car, he smelled the smell of burning, fire burning vehicle at this time.

This mechanical design also appears on a simple structure in the periphery of the bottom cover and consider additional protection, you can get immediate results.

We make things happen this year, the manufacturers removed, you can then think about a car on fire outside the cell or battery? A large part of the load cell is outside the peripheral portion of the cable overheating lit things some more.

Here we can be divided into three basic, because the nature of fire:

Released in accordance with the design intent and outside the combustion heat within the battery, 

1. The combustible gas inside the battery release ignition

2. Flammable liquid inside the battery release + Flash point: here including electrolyte leakage and coolant leaks in two parts.

We can release heat energy battery systems to consider:

1. Battery Pack or Battery Cell Overcharge

Overcharge release of thermal energy in general is indeed more common reason, the storage battery pack of solar powered portable generator level thermal runaway event, can be broken down into more down the battery (modules monomer overcharge), evaporated electrolyte battery overcharge and overheating, as well as It is the battery remaining capacity (SOC) calculation error caused by over-charging, high SOC state, not in accordance with energy recovery protection cause, and the charging control program stuck due to overcharging.

2. A Person Short Circuit Overcurrent Heat Release

Lithium Battery Explosion

Battery pack high voltage circuit failure cause a short circuit, distributing heat. The main battery pack is an internal short circuit and external short circuit, causing the conductors and connectors overheating, caused by overheating of the monomer subsequent thermal event, is further broken down to be broken down into short-circuit caused by overheating of the module components. Eg short circuit module level, a short circuit within the battery pack, the external corrosion / conductive liquid into a short circuit caused.

3. High-impedance Connection of Heat

Fault battery pack high-voltage circuits, resulting in high resistance appearing at the position charging and discharging circuit, the current rise in the temperature of the high resistance point that could cause a fire and subsequent heat adjacent material spread. Trunk junction poor contact, corrosion caused by heat.

4. The Internal Resistance of The Battery Overheating and Internal Promotion

Monomers to produce a combustible gas exhaust, followed by a heat source (arc monomer thermal runaway) lead to the battery system, surplus heat. Monomeric single point of failure as defined thermal runaway experiment can be considered a single monomer extended to the whole aspect, in the given conditions, each battery pack for portable solar power generator will achieve record correspondent, some reference to the role, but the experimental conditions and the occurrence of failure is not It may be completely consistent.

The article comes from

Storage Batteries Made Significant Breakthrough

High-performance chemical storage batteries and portable solar power generator power plant key technology research, supported by high energy density, low-cost new supercapacitor key technologies , long-life lithium manganese battery energy storage system and key technology demonstration and other topics are significant progress was made, it has recently passed the technical acceptance.

Portable Solar Generators
New Super Capacitor

In the "new super capacitor", the preparation of technical bottleneck breakthrough high energy density and long life high power density supercapacitors portable solar power generator developed porous graphene, high voltage electrolyte salt and electrolyte, separator and other cellulosic materials, the development of dry preparing an electrode film test technology, breaking the (3.0V/12000F) supercapacitor industrialization of core technologies, products can be recovered in the machinery, rail vehicles supercapacitor respect at home and abroad to obtain applications. From domestic materials, devices integrated into the system formed in the super capacitor core technology system, changing the super capacitor during the Eleventh Five by the monopoly of foreign products.

Long-life Lithium Manganese Battery Energy Storage System

In the "long-life lithium manganese battery energy storage system", the industrialization of key technologies mastered the low-cost long-life lithium-ion energy storage system, launched a layered lithium manganese oxide, lithium manganese oxide single crystal surface coating, aluminum, cobalt Study co-doped material, a hard carbon anode material asphalt and resins derived function of the electrolyte studies, as well as single cells, modules and energy storage system of lithium manganese oxide cathode, single life expectancy has more than 3,000 times, some 6,000 times. Completed the development of two sets of 50kW / 100kWh level layered lithium manganese oxide / hard carbon lithium-ion battery energy storage system and the demonstration run, portable solar power generator is the first in the world; while the development of energy storage 20kWh solar home systems, 3kWh standby emergency power demonstration applications.

All-solid-state Lithium-ion Storage Battery

In the "all-solid lithium-ion storage battery", the successful development of high conductivity Li2S-P2S5 binary system and Li2S-GeS2-P2S5 ternary solid electrolyte mastered the system preparation Li2S-P2S5 glass-ceramic solid electrolyte material preparation method, the amorphous precursor made great breakthrough to achieve a stable production of high efficiency.

It has now achieved kg capacity sulfide solid electrolyte prepared. Development of the high nickel component layered cathode material having a core-shell structure and composition gradient. With the above binary sulfide solid electrolyte and cathode, developed capacity of 4.0Ah and 8.0Ah solid-state lithium batteries, the number of cycles at room temperature reached 500 times , and optimized assembly process proposed large-scale all-solid-state lifepo4 battery in soft packages solar power portable generator, promoted the industrialization process of all-solid lithium-ion battery.
self balancing scooter battery
New LifePo4 Batteries Chemical Energy Storage

In the "new type of lithium sulfur battery chemical energy storage", the development of high-energy density lifePo4 batteries technology preparation, development of 35Ah lithium-sulfur battery specific energy 566Wh / kg (25 ℃ test), reached the world advanced level. 1kWh initial development of lithium-sulfur batteries and large-capacity 12kWh llifePo4 batteries, solar power portable generator achieved its coupling power demonstration. Using elemental sulfur, high-capacity lithium-sulfur batteries and battery technology products have the potential when used as a long-endurance UAV airborne energy systems and other areas of application prospects.

Low-cost Lithium Titanate Energy Storage Lithium-ion Battery

In the "low-cost lithium titanate energy storage lithium-ion battery", the amount of material to get through the low-cost production, long life and high consistency and battery modules, portable solar power generator plant demonstration and promotion of the whole industry chain, to build a solar power portable generator system based on lithium titanate anode material demonstration of mobile storage devices, optical storage demonstration was 0.5MWh / 1MW lithium titanate energy storage power station, laid the foundation for lithium titanate energy storage applications.

To some extent, to meet the renewable energy and smart grid scale energy storage needs, and promote the orderly development of wind, solar powered portable generator and rational allocation of resources, improve the intermittent new energy grid technology, energy storage batteries for China material - batteries - integration - demonstration chain provides a more complete technical support system, building industry internationally competitive platform for future sustainable development of the industry and promote the development of China's storage industry, to enhance China's energy can strategic position of sustainable development, broad market prospects.

The article comes from

LifePo4 Storage Battery For Portable Solar Power Generator

Lithium-iron battery solar powered portable generator system can be used as a variety of electric power and stability of the buffer between the needs of the power can be increased as wind, solar and other unstable power generating capacity. Wind power generation system due to changes in wind speed and cause the output power of the oscillation, and portable solar power generator system can be fast response speed, almost equal to the charge-discharge cycle characteristics provide stability and reactive power compensation for the fan output. At the same time, the energy storage system can adjust the voltage and off-grid power system frequency control system.

Control System

Lithium-Iron battery solar power portable generator system consists of a programmable logic controller (PLC) and human machine interface (HMI) control. One of the key functions of the PLC system is to control the energy storage system charging time and rate. For example: PLC electricity prices may receive real time data, and based on the maximum allowable electricity demand, as well as the state of charge Compare prices peak / off-peak time, decide how quickly to re-charge the lifePo4 batteries system. This decision is dynamic and can be optimized according to specific circumstances. Through standardized communication input control signal and power supply, which is integrated with the rest of the portable solar power generator system. It can be accessed through a dial-up or Internet. It has multiple layers of defense to limit access to its various functions, and provides customized reporting and alarm functions for remote monitoring.

Power Conversion System (PCS)

Function power conversion system is the lifePo4 batteries charge and discharge, and to provide an improved quality of power supply voltage and frequency control support for the local grid. It can have a complex, fast acting, multi-quadrant, the dynamic controller (DSP), with a dedicated control algorithms to the entire range of switching the output device, i.e., the cycle from absorbing full power. Reactive power demand as well as any combination of active and reactive power, it can work properly.

Lithium iron Stack

The stack is made of many cells. Iron lithium battery portable solar power generator system to economically store and provide large-scale power on demand, is the main mode of fixation. It is a long-life, low maintenance, efficient technology to support extensions stepless power and storage capacity. Energy storage system for renewable energy providers, power companies and end-users are particularly effective.

Deferred grid fixed investment, as well as load shifting applications. Solar power portable generator system can also serve as a communication station and substation to provide backup power to be applied.  lifepo4 48v energy storage system for environment-friendly, in all energy storage technologies for minimal ecological impact, but not to lead or cadmium and other elements of the main reactants.

Renewable Energy
E-bike Batteries Pack
Lithium-Iron battery energy storage system can be used as a variety of electric power and stability of the buffer between the needs of the power can be increased as wind, solar and other unstable power generating capacity. Wind power generation system due to changes in wind speed and cause the output power of the oscillation, and portable solar power generator system can be fast response speed, almost equal to the charge-discharge cycle characteristics provide stability and reactive power compensation for the fan output. At the same time, the energy storage system can adjust the voltage and off-grid power system frequency control system.

Power Supply in Remote Areas

In the sparsely populated remote areas, such as islands, diesel generators often as a single source of energy. Diesel generators are often due to changes in load and in a non-rated power, which makes fuel-efficient reduced by about 30%.

Off-grid solar power supply system configuration storage system can effectively reduce diesel consumption, operation and maintenance costs, greenhouse gas emissions and extend the life of diesel engines.

Wind power and photovoltaic power generation accounted for the total proportion of diesel power increasing, while the proportion reached 30% of the time, it brings instability will directly reduce the reliability of the local power grid, should be more limited increase in renewable energy electricity. However, by configuring the portable solar power generator system, the ratio may be 100%, and the project payback period be shortened to three years. With rising fuel prices, the economy will be more significant.

The article comes from

Tuesday, 25 October 2016

Research And Development New Battery Technology

In addition, energy storage research also has multiple problems, such as foam cells, flow batteries to a variety of chemical materials, no one knows which technology will attract the most funds and research heat.

Lux Research reports that the energy storage investment of more than 40 billion US dollars, such as solar power generator and wind power, the development of next-generation batteries, non-lithium-ion battery startups in the past eight years, an average of only 4 million funds, Tesla investment in lithium-ion battery factory Gigafactory invested 5 billion US dollars .

R & D new battery material threshold is very high, just to build a small production line to study the details into production, it is necessary to 500 million US dollars, car manufacturers may also take several years to test the new battery system before deciding whether to purchase, if Your company has only $ 5 million in capital a year, making it hard to invest $ 500 million in manufacturing.

Leyden Energy, A123 Systems, Seeo, Sakti3 are not looking for the end because of the factors such as production, price and other factors that investors will not be able to achieve, even if the new battery manufacturers commercialize new technology, and will face the problem of increasing production and looking for buyers.

The world's three major battery manufacturers, Samsung, LG, Panasonic on the new chemistry and significantly change the battery technology are not too interested in, they would rather gradual improvement in the existing technology. The battery technology can improve device application, lighten the device weight, such as when people take solar powered portable generator to travel.

Although the first lithium-ion battery as early as the 1970s to come out, but now technology has been getting better and better, which is innovative battery technology, the most reluctant to mention, and they face the biggest problem.

The article comes from

Friday, 14 October 2016

Top 4 Tips to Maintain UPS LifePo4 Batteries

Many people think that the lifePo4 batteries is maintenance-free, especially when using a UPS power supply, this idea is even more apparent. But in fact, the problem is due to the lack of maintenance caused by battery failure in all UPS's share is quite high.

Many people think that the lifePo4 batteries is maintenance-free, especially when using a UPS power supply, this idea is even more apparent. But in fact, the problem is due to the lack of maintenance caused by battery failure in all UPS's share is quite high. Therefore, routine maintenance of UPS lifePo4 batteries, UPS will largely extend the battery life and reduce the failure rate. This article will introduce you to UPS lifePo4 batteries maintenance methods.

Maintaining Proper Temperature

Generally, factors affecting lifePo4 batteries life is greater ambient temperature. The optimal ambient temperature is generally required for battery manufacturers is between 20-25 ℃. Although the temperature rise of the battery discharge capacity has increased, but at the expense of lifePo4 batteries life is shortened. According to tests measuring the ambient temperature once more than 25 ℃, every increase of 10 ℃, the battery life will be shortened by half. UPS lifePo4 batteries currently used are generally maintenance-free sealed lead-acid battery design life expectancy is five years, which can be achieved at battery manufacturer demanding environments. The lifepo4 battery also can be used in solar power portable generator. Not reach the environmental requirements, there is a great difference in the length of its life. In addition, to improve the ambient temperature, it will cause the battery internal chemical activity increased, resulting in a lot of heat, in turn prompting the ambient temperature rises, this vicious cycle will accelerate shorten lifePo4 batteries life.

Regularly Charge and Discharge

UPS power supply in the float voltage and discharge voltage at the factory have been commissioning rating, while the discharge current size increases as the load increases, the use should be reasonable to adjust the load, such as the control computer and other electronic equipment It uses several. Under normal circumstances, the load should not exceed 60% UPS rated load. In this range, the lifePo4 batteries discharge current will not over-discharge.

UPS due to the long connected to the mains, the supply of high quality, rare power cut use of the environment, the battery will be a long period of float charge state, the course of time will lead to battery chemical energy and electrical energy into each activity decreased, accelerated aging and shorten life. Thus, generally every 2-3 months should be fully discharged once the discharge time can be determined based on the lifepo4 battery pack capacity and load size. After a full load discharge is complete, the required recharge more than 8 hours. 

Use of Communications Capabilities

Currently, the vast majority of large and medium-sized UPS are equipped with computer communication and control procedures operability. Install the appropriate software on the PC connected to UPS through the serial / parallel port, run the program, you can use the computer to communicate with the UPS. Generally have information query, parameter settings, set the timer, automatic shutdown and alarm functions. Through information query, you can get the mains input voltage, UPS output voltage, load utilization,lifePo4 batteries capacity utilization, internal temperature and mains frequency information; through parameter settings, you can set the basic characteristics of UPS, battery time and can be maintained battery runs out alarms. Through these intelligence operations, which greatly facilitates the use of lifePo4 batteries and UPS power management.

The Timely Replacement of the Waste or Bad Battery

Currently the number of medium and large UPS lifePo4 batteries power supply is equipped from 3-80 dollars, or even more. These individual cells through a circuit connected to form a battery pack to meet the needs UPS DC power supply. UPS running in continuous use, due to the difference in performance and quality on individual lifePo4 batteries performance, storage capacity is mainly the damage is inevitable. When the battery pack in a / some cells are damaged, the maintenance personnel should be checked for each battery test, to exclude damage to the battery. When replacing a new battery, it should seek to buy with the same type of battery manufacturers prohibit anti-acid batteries and sealed batteries, mix batteries of different specifications.

This article comes from

5 Tips for Choosing Best UPS LifePo4 Battery

Determine the required UPS capacity: Calculate the sum of all load S = S1 + S2 + ...... + Sn Unit: VA. Select UPS capacity ≥S ÷ 0.8 (consider the impact resistance and the need for expansion of the UPS).

UPS to determine the required type: according to the load on the output stability, switching time, the output waveform is determined by selecting on-line, line-interactive, backup lifePo4 battery pack. Output line UPS stability, transient response capability than the other two strong ability to adapt to non-linear loads is also strong. Some of the more sophisticated equipment and more important requirements for the use of equipment-line UPS. If you are using a generator with a short delay UPS, recommended on-line UPS, because the generator voltage and frequency ordinary poor stability, with back-line interactive and it may not work properly. Some brands of UPS (on-line) don't match with the generator, it will switch to bypass power, to understand clearly the time of purchase. 

Determine the required lifePo4 batteries backup time: According to the power-down, the equipment required working hours. Time-lapse type battery costs may exceed UPS host itself. Due to the high value of the lifePo4 batteries, there are more counterfeit goods, to select high degree of credibility of suppliers, which UPS system reliability is critical.

Additional features: To improve the reliability of the system by lifePo4 batteries, we recommend using a redundant UPS system, can be considered in series or in parallel heat hot backup redundant. Small capacity UPS (1 ~ 2KVA) can also use redundant switches. You can use remote monitoring panel, realized at the distal end monitoring and control of the UPS work. You can use monitoring software, intelligent management computer and the UPS between. You can choose a network adapter to achieve the UPS network management (based on SNMP). In some rainy thunder area, it can be used with SPD. 

This article comes from

Solar Power Battery Storage System The Principle of Charging and Discharging

Solar Power Battery Storage System

Solar power battery has a high operating voltage, high energy density, a series of unique advantages of long cycle life, environmental protection and so on. And supports stepless extension. After the composition of the energy storage system for large-scale energy storage.

Solar storage batteries energy storage system consists of Solar power battery group, a battery management system (Battery Management System, BMS), commutation devices (rectifiers, inverters), central monitoring system, transformers and other components, as shown in FIG.

Solar power battery energy storage system of energy conversion principles. Charging stage, intermittent power supply or power grid as the energy storage system is charged, the AC to DC rectifier rectifier after charging the battery energy storage module to store energy; discharge phase, the energy storage system to the grid or the load is discharged, the battery energy storage module through the inverter DC to AC inverter, via the central monitoring system controls the inverter output, enabling the load to the grid or to provide a stable power output.

Battery charge and discharge principle

Charge-discharge reaction of Solar power battery is between solar power battery and FePO4 two phases. During charging, Solar power battery ions moving away from FePO4, during discharge, lithium ions FePO4 formed Solar power battery.

When charging the battery, lithium ions migrate from the solar power batteries crystals to the crystal surface, under the action of the electric force, into the electrolyte, and then through the membrane, and then the electrolyte migrate to the surface of the graphite crystal, then the character is embedded in graphite. At the same time, the flow of electrons through a conductor of positive electrode collector foil by tabs, battery positive column, the external circuit, the negative pole, the negative electrode lug flow battery cathode copper foil collector, and then flows through a conductor graphite anode so that the negative electrode Heda to balance. After the lithium ions from the Solar power battery deintercalation of Solar power battery is converted to iron phosphate.

When the battery is discharged, the lithium ion deintercalation from graphite crystals out into the electrolyte, and then through the membrane, through the electrolyte to migrate to the surface of Solar power battery crystals and then re-embedded into the crystal lattice of Solar power battery. At the same time, the flow of electrons through a conductor foil negative electrode collector by tabs, battery negative column, the external circuit, the positive pole, the cathode tabs flow battery cathode foil collector, and then flows through the conductive body iron phosphate lithium anode, the positive electric Heda to balance. Lithium-ion iron phosphate crystals embedded in the rear, into iron phosphate Solar power battery.

This article comes from