This is a warning for those looking at 340AH Lifepo4 Batteries.
Warning: Issues with 51.2V 340Ah Batteries Made by Gotion
We would like to inform our customers about a serious concern regarding 51.2V 340Ah batteries especially those with the cells made by Gotion. There have been known production issues with these cells, and as a result, B grade sellers have been attempting to sell these faulty units for over a year.
Key Points:
Production Issues: Gotion encountered significant production issues with their 340Ah cells. These problems have led to a number of quality and performance concerns.
B Grade Cells: These problematic cells are being sold as B grade, meaning they do not meet the original quality standards and may have defects.
Long-Term Sales: Despite these issues, sellers have been trying to offload these subpar cells for more than a year, often at attractive prices to entice buyers.
Risks of Using B Grade 340Ah Batteries:
Reduced Performance: Expect lower efficiency and potential inconsistencies in power output.
Safety Hazards: Faulty cells can pose significant safety risks, including overheating, leaks, or even fires.
Shortened Lifespan: These cells may not last as long as A grade cells, leading to a need for earlier replacement and additional costs.
OUR CHINESE PARTNERS have rated them as some of the lowest quality 3.2v cells on the market. So please be careful. The capacity variances can be up to 20% and the expected lifespan has been quoted at only 2500 cycles by the wholesaler. Ive never seen a cell that low, not since before 2020.
Recommendations:
Verify Source: Ensure that you are purchasing batteries from reputable sources and confirm the grade of the cells.
Check Documentation: Look for any documentation or certifications that guarantee the quality and safety of the batteries.
Avoid Suspicious Deals: If a deal seems too good to be true, it likely is. Be wary of heavily discounted 340Ah batteries, especially if the seller cannot provide solid proof of their grade and quality.
At Lifepo4 Australia, we are committed to providing only the highest quality products to our customers. We encourage you to reach out to us for any questions or concerns about battery purchases. Your safety and satisfaction are our top priorities.
Stay informed and purchase wisely.
Gotion’s 3.2V 340Ah LiFePO4 cells have encountered significant production issues, leading to a number of concerns for potential buyers. These issues primarily involve quality control problems that have resulted in inconsistent performance and reliability across batches. Due to these problems, a large number of B-grade cells have been circulating in the market for over a year, often sold at discounted prices by various vendors.
Key points to be aware of:
Inconsistent Performance: Many users have reported variability in capacity and performance among the cells. Some cells fail to meet the advertised capacity of 340Ah, causing issues in applications requiring consistent and reliable power output.
Balancing Issues: There have been frequent reports of difficulties in balancing these cells, with some cells showing significantly different voltage levels under the same charge/discharge conditions. This can lead to premature wear and potential safety risks.
Safety Concerns: Given the quality issues, there is an increased risk of thermal events, especially under high charge or discharge conditions. Proper handling and rigorous testing are essential before deploying these cells in any critical application.
Long-Term Reliability: The long-term reliability of these cells remains questionable due to the production flaws. This includes a higher than usual rate of degradation and potential failures over time, which can be costly and hazardous.
It is crucial to purchase from reputable sources and verify the authenticity and quality of the cells before use. Consider requesting detailed test reports and certification to ensure you are getting Grade A cells.
For more detailed insights, you can refer to discussions on platforms like DIY Solar Power Forum and product details on sites like TezPower and Lightning Energy
Why Flexible Busbars for LiFePO4 Battery Cells are mostly a Gimmick
Introduction In the world of LiFePO4 battery cells, flexible busbars have gained popularity as an innovative solution promising improved performance and longevity. However, some industry experts and battery enthusiasts argue that this is merely a marketing gimmick designed to boost profit margins. This article explores the reasons behind this skepticism and presents both sides of the argument, including real-world accounts.
Reasons Why Flexible Busbars Are Considered a Gimmick
Limited Swelling in LiFePO4 Cells
Argument Against: LiFePO4 battery cells are known for their stability and minimal swelling compared to other battery chemistries. The structural integrity of these cells typically does not necessitate flexible connections. The argument here is that the batteries would never swell enough to require a busbar that can extend its length, making the flexible feature redundant.
Real-World Account: Many DIY battery builders and professionals have reported that their LiFePO4 battery packs remain structurally sound over long periods, with no significant swelling that would justify the need for flexible busbars.
Increased Complexity and Cost
Argument Against: Flexible busbars add unnecessary complexity and cost to battery pack construction. Traditional rigid busbars are sufficient for maintaining solid connections and managing current flow. The additional expense of flexible busbars may not translate into any significant performance benefits, thus being viewed as an upsell tactic.
Real-World Account: Most battery assembly experts have highlighted that they have successfully used rigid busbars for years without any issues related to swelling or connection failures. These experts argue that the cost-benefit ratio of flexible busbars does not favor their use in practical applications.
Potential for Increased Resistance
Argument Against: The materials and design used in flexible busbars can sometimes introduce additional electrical resistance, which may negatively impact the efficiency of the battery pack. In contrast, rigid busbars typically offer lower resistance and more reliable performance.
Real-World Account: Engineers and battery technicians have noted that maintaining low resistance connections is critical for high-performance battery systems. Any additional resistance introduced by flexible busbars could potentially degrade the overall efficiency of the system.
Arguments in Favor of Flexible Busbars
Improved Vibration Resistance
Argument For: Flexible busbars can absorb and dissipate vibrations more effectively than rigid busbars. This feature can be particularly beneficial in applications where the battery pack is subject to constant movement or vibrations, such as in electric vehicles or portable power systems.
Real-World Account: Some users in the automotive industry have reported that flexible busbars contribute to the longevity and reliability of battery packs by reducing the stress on connections due to vibrations.
Ease of Assembly and Maintenance
Argument For: Flexible busbars can simplify the assembly process, especially in battery packs with complex geometries or tight spaces. They allow for easier alignment and connection of cells, which can reduce assembly time and potential errors.
Real-World Account: Battery assembly technicians in some manufacturing setups have expressed that flexible busbars make the assembly process more straightforward, reducing the likelihood of connection issues during installation.
Conclusion While flexible busbars for LiFePO4 battery cells are marketed as an innovative solution, many industry experts argue that they are unnecessary and primarily serve as a way to increase profit margins. The stability and minimal swelling of LiFePO4 cells, coupled with the additional cost and potential for increased resistance, make flexible busbars a questionable investment for many applications. However, in specific use cases involving high vibration environments or complex assembly requirements, flexible busbars may offer some advantages. Ultimately, the decision to use flexible busbars should be based on the specific needs and constraints of the battery pack design.
The Yixiang DIY Battery Box is a customizable battery enclosure designed for DIY battery builders. It is sometimes promoted among those who assemble their own battery packs for various applications, including solar energy storage, electric vehicles, and backup power systems. Here are some key features and aspects of the Yixiang DIY Battery Box:
IMPORTANT NOTE – BE CAREFUL! these companies start off cheap and end up just as expensive as all the others. Make sure you have calculated ALL THE COSTS and never agree to a sale until you have had TIME TO THINK about your purchase
Modular Design: The battery box is modular, allowing users to configure it to fit different battery cell sizes and quantities. This flexibility makes it suitable for a range of battery pack designs.
Durability: Made from high-quality materials, the box is designed to be durable and provide good protection for the battery cells inside. It is often constructed from fire-resistant and impact-resistant materials to ensure safety.
Ease of Assembly: The design of the Yixiang DIY Battery Box emphasizes ease of assembly, with clearly marked components and straightforward instructions. This makes it accessible even for those with limited technical expertise.
Ventilation and Cooling: Many models include features for ventilation and cooling, which help to maintain optimal operating temperatures for the battery cells, thereby enhancing performance and longevity.
Compatibility: The battery box is compatible with various battery chemistries, including LiFePO4, NCM, and others. This versatility allows users to choose the best battery type for their specific needs.
Customization Options: Users can customize the box with additional features such as BMS (Battery Management System) integration, LCD screens for monitoring, and various connectors and terminals to suit their application.
Portability: Designed with portability in mind, many models include handles or wheels, making it easy to transport the assembled battery pack.
Safety Features: The Yixiang DIY Battery Box often includes multiple safety features such as short circuit protection, overcharge and over-discharge protection, and temperature sensors to ensure the safe operation of the battery pack.
If you need more detailed specifications or information about a particular model, please let me know!
The process of purchasing from China lithium battery cells, particularly for do-it-yourself (DIY) projects, is fraught with complexities and pitfalls, largely stemming from issues of quality and shipping. As a specialist in the field with extensive experience, I aim to elucidate these challenges, providing insights that stem from my personal journey in navigating this treacherous terrain.
The Allure and Risks of Using Alibaba
Many importers continue to be drawn to platforms like Alibaba due to apparent cost savings and convenience. However, a significant risk lurks beneath the surface: approximately 90% of importers end up with subpar, or “B grade,” cells. This pervasive issue is largely attributable to the shipping practices and the inability to visually distinguish between A and B grade cells.
Why Most Cells Are B Grade
The core of the problem lies in the shipping practices employed by many Alibaba vendors. These sellers often resort to “black market shipping,” where containers filled with dangerous goods (like lithium batteries) are not properly declared. This involves using what is known in Chinese as “special line” shipping, which typically involves bribes to customs officials in both China and Australia.
This unorthodox approach allows sellers to dramatically reduce shipping costs—sometimes by half compared to reputable companies like EVE Energy, which adhere strictly to international shipping regulations for dangerous goods. EVE Energy, being a billion-dollar enterprise, cannot risk the legal and ethical implications of concealing dangerous goods in regular shipments.
The Difference Between A and B Grade Cells
From a technical perspective, A and B grade cells may appear identical, but their performance and reliability diverge significantly. EVE Energy, for instance, implements rigorous testing procedures during their 3-4 week manufacturing process. This includes specialized charging processes, capacity checks, and voltage tests, which classify cells into categories like A+, A, B, and B- grades. Up to 40% of cells are downgraded to a lower grade due to identified defects during these tests.
Our Approach: Ensuring Quality and Compliance
Given the complexities of legally and safely importing lithium cells, I have taken the route of organizing my own shipping and securing necessary certifications for transporting dangerous goods. This approach, while time-consuming and complex, ensures that I provide only A+ grade cells, unlike the prevalent B grade cells that flood the Australian market through less scrupulous importers.
The Misrepresentation by Alibaba Sellers
A common tactic among Alibaba sellers is falsely representing B grade cells as A+ grade. This misrepresentation is facilitated by the structure of the supply chain, where cells are warehoused en masse and drop-shipped by vendors who often operate merely as call centers. The consequence is a market flooded with inferior cells sold under the guise of top-tier quality.
Conclusion: Navigating the Lithium Cell Landscape
The challenges of purchasing lithium battery cells from China revolve around navigating through a murky landscape riddled with deceptive practices and regulatory challenges. My expertise and commitment to quality and safety have allowed me to overcome these barriers, ensuring that I can provide genuinely high-grade lithium cells.
This situation underscores the importance of rigorous due diligence and understanding the intricate dynamics of international shipping and quality control. By sharing my experience, I aim to enlighten potential buyers and DIY enthusiasts on the pitfalls of the market and the critical importance of sourcing from reliable and ethical suppliers.
In simpler terms, buying lithium battery cells from China can be tricky. Many buyers (importers) get tempted by lower prices on platforms like Alibaba, but often end up with lower-quality, “B grade” cells due to shady shipping practices where sellers don’t declare dangerous goods properly to cut costs. This is risky and against the law.
On the other hand, reputable companies like EVE Energy follow strict shipping rules, which makes their cells more expensive but ensures they are of high quality. I’ve gone the extra mile to organize my own shipping and make sure everything is above board, which means I only provide top-quality, “A+ grade” cells.
To put it plainly, if you’re looking to buy lithium cells, it’s crucial to understand that the cheapest option might end up costing you more in the long run due to poor quality. It’s better to pay a bit more for cells that are safely and legally shipped, ensuring you get what you pay for—reliable and effective batteries.
To clearly highlight our approach: we manage our own shipping and customs processes entirely within legal frameworks. This commitment to legality and ethical practices sets us apart from many sellers around the world who often resort to shortcuts like purchasing from Alibaba to save on shipping costs.
By purchasing in bulk and overseeing every step from customs clearance to delivery, we ensure that we provide only A+ grade cells. This direct involvement allows us to maintain high standards of quality and safety, unlike many other sellers who compromise on these aspects to reduce expenses. This unique approach ensures that our customers receive the best possible product without the common risks associated with improperly handled imports.
Probably the best information we can give you, is to outline the actual practices
EVE might sell a battery for $68-73 USD A+ grade Shipping might be $600-800 AUD for 16 cells (Its always more expensive because its legal shipping)
Alibaba sellers buy B grade cells from anywhere between 50-75% of the A+ grade price. This means $34-56 USD
The Alibaba seller will then quote you $64-80 for that same cell But not only that there shipping quote to you might be $400-600. The price is not that important, BUT they are also making profits on the shipping because its not DG shipping. Its illegal
They do not declare the Batteries as DG in Australia either, so they pay $100’s of dollars less for this shipping pathway.
This is all profit. The process has been improved over a few years. So its now down to only a couple of shipping companies who handle all of the deliveries in Australia
In many cases, they do not pay GST either or only a tiny fraction of what should be paid. This is our money, our countries money, that is supposed to go back into, schools and hospitals and such for the benefit of our country. No in the pockets of overseas companies who are also selling bad cells to us.
The total price is always much lower through Alibaba sellers. The Alibaba seller makes $20-35 USD more per cell. This means they can put signinificant effort into replacing a QR code with valid data.
The Laser etching technique which is used to replace a QR code, machine is a very cheap investement when we are talking about replacing the QR code of thousands of cells. The investement into this machinery and process is now extremely profitable.
The cells are purhased in lots of thousand and hundreds of thousands. They are transported to a warehouse/ processing centre. where they are graded again and then relabelled with a new QR code. The QR code is from genuine A+ grade cells. A QR code is just letters and numbers. So this data is taken from a genuine batch of A+ grade cells. The spreadsheets from EVE A+ grade cells are used to create what appears to be A+ grade cells. This process costs about $1.50 USD per cell.
The IEC 62619:2022 standard specifies requirements and tests for the safe operation of secondary lithium cells and batteries used in industrial applications. This includes stationary applications like energy storage systems and mobile applications such as electric vehicles. The standard is crucial for manufacturers, integrators, and end-users who rely on lithium battery technology, as it addresses several critical aspects of safety and performance.
Key Aspects of IEC 62619:2022
Scope and Application:
The IEC 62619:2022 standard is specifically designed for secondary lithium cells and batteries for industrial applications. It does not cover batteries for consumer electronics or those used in electrically propelled road vehicles.
It is applicable to cells and batteries regardless of the lithium-ion chemical composition.
Safety Requirements:
The standard includes stringent safety requirements for lithium-ion batteries to minimize risks such as thermal runaway, fire, and electric shock. These requirements are designed to protect users, technicians, and nearby equipment from potential hazards.
It mandates measures for the protection against mechanical abuses, electrical abuses (like overcharge and deep discharge), and thermal abuses, ensuring the batteries can withstand harsh conditions without failing.
Testing Procedures:
IEC 62619:2022 outlines comprehensive testing procedures to verify compliance with its safety requirements. These tests assess the battery’s ability to safely charge and discharge, its resistance to mechanical stress, and its thermal stability, among other factors.
The tests include, but are not limited to, short circuit conditions, overcharge, forced discharge, thermal abuse, and mechanical shock tests.
Performance Metrics:
While the primary focus of IEC 62619:2022 is on safety, it also considers performance aspects such as cycle life, capacity, and efficiency under various conditions, ensuring that the batteries not only are safe but also perform reliably over their intended lifespan.
Documentation and Marking:
The standard requires clear documentation for the safe handling, operation, and maintenance of lithium-ion batteries. This includes data sheets, instructions for use, and safety warnings.
Batteries must be marked with specific information, including manufacturer details, type, electrical characteristics, and safety symbols, as applicable.
Environmental Considerations:
Although IEC 62619:2022 focuses on safety and performance, manufacturers and users are encouraged to consider environmental impacts, including recycling and disposal of lithium-ion batteries in accordance with local regulations and best practices.
Importance of IEC 62619:2022
Compliance with IEC 62619:2022 is crucial for manufacturers and suppliers of lithium-ion batteries for several reasons:
Safety: It ensures that products are designed and tested to minimize risks of injury or damage.
Market Access: Many countries and industries require compliance with international standards like IEC 62619:2022 for market entry.
Quality Assurance: Adherence to the standard reassures customers and end-users about the quality and reliability of the batteries.
Regulatory Compliance: It helps manufacturers navigate the complex landscape of global regulations concerning lithium-ion batteries.
For the most current and detailed information, including any amendments or interpretations, directly consulting the IEC 62619:2022 standard document and associated regulatory bodies is recommended.
When examining the landscape of lithium iron phosphate (LiFePO4) batteries, SOK and EG4 stand out for their quality, reliability, and performance. Both brands have garnered attention in the renewable energy sector, particularly among solar energy enthusiasts and off-grid living proponents. This analysis will delve into the technical aspects of popular LiFePO4 batteries from SOK and EG4, highlighting their features, performance, and suitability for various applications.
Capacity and Energy Density
SOK LiFePO4 Batteries: SOK batteries are known for their true-to-advertised capacity, typically offering a range from 100Ah to 200Ah per battery. This capacity is ideal for a range of applications, from home energy storage systems to RV and marine applications. The energy density of SOK batteries is optimized for longevity and reliability, with a focus on providing consistent power output over an extended period.
EG4 LiFePO4 Batteries: EG4 also provides a range of capacities, similar to SOK, with models also available in the 100Ah to 200Ah range. The energy density of EG4 batteries is competitive, ensuring that they occupy less space while delivering equivalent power, which is particularly advantageous in mobile applications and installations where space is at a premium.
Cycle Life and Longevity
SOK LiFePO4 Batteries: SOK batteries boast a significant cycle life, often rated at over 4000 cycles at 80% depth of discharge (DoD), which translates to more than a decade of use under normal conditions. This long lifespan is a testament to the quality of the battery construction and the efficiency of the internal BMS (Battery Management System).
EG4 LiFePO4 Batteries: EG4 matches the industry standard with a similar cycle life, also claiming upwards of 4000 cycles at 80% DoD. This level of performance indicates that EG4 batteries are built to last, providing users with a reliable power source over many years.
Charging and Discharging Rates
SOK LiFePO4 Batteries: SOK batteries are designed to accommodate flexible charging and discharging rates, suitable for various applications. Typically, they can support continuous discharge rates up to 1C and charge rates up to 0.5C. This means a 100Ah SOK battery can be discharged at 100A and charged at 50A, making them versatile for different energy needs.
EG4 LiFePO4 Batteries: EG4 batteries offer similar charging and discharging capabilities, with most models supporting 1C discharge and 0.5C charge rates. This compatibility with high-rate charging and discharging makes EG4 batteries suitable for applications requiring rapid energy availability and storage.
Built-in Battery Management System (BMS)
SOK LiFePO4 Batteries: The BMS in SOK batteries is designed for efficiency and safety, providing overcharge, over-discharge, over-current, and temperature protection. Additionally, the BMS facilitates cell balancing, ensuring that each cell in the battery operates optimally, which is crucial for maintaining the battery’s health and extending its lifespan.
EG4 LiFePO4 Batteries: Similarly, EG4 batteries come equipped with a sophisticated BMS that offers protection against common battery issues, including overcharging, deep discharging, and overheating. The BMS also supports cell balancing, which is essential for the longevity and performance of the battery.
Price and Value
SOK LiFePO4 Batteries: SOK batteries are generally considered to offer excellent value for money, given their longevity, reliability, and performance. While they may carry a higher upfront cost compared to traditional lead-acid batteries, their extended lifespan and lower total cost of ownership make them a financially sound investment over time.
EG4 LiFePO4 Batteries: EG4 batteries are competitively priced, offering a similar value proposition to SOK. The brand is known for providing high-quality batteries that meet the demands of rigorous applications, ensuring that consumers receive a product that balances cost with performance and durability.
Conclusion
Both SOK and EG4 LiFePO4 batteries offer exceptional quality, performance, and reliability for a wide range of applications. The choice between the two will largely depend on specific application requirements, brand preference, and potentially the level of customer service and support offered by the company. In terms of technical specifications, both brands are closely matched, providing durable, high-performance batteries that promise long-term reliability and efficiency for energy storage needs.
Comparing the EVE LF304 to the LF280, LF280K, and LF280k v3, MB30, MB31 we can analyze the key differences and similarities among these popular Lifepo4 cells.
You can also find out why the next generation of MB (Mr Big) cells is better than the last, mostly due to the new stacking technique being employed by just a small number of LFP manufacturers. At this stage CATL, EVE have next generation cells, not yet freely available. But in the near future, you will be able to purchase these cells if you don’t buy them from the grey markets.
EVE LF304
LF304 EVE
The EVE LF304 has a cycle life of 4000 at 0.5C/0.5C. Giving it an estimated lifespan of up to 11 years. The EVE LF304 is EVE’s high power cell, with thicker coatings,
Capacity: 304Ah Nominal Voltage: 3.2V
LIFEPO4 AUSTRALIA OPINION Cycle Life @ 1C : 2000 Cycles Cycle Life @ 0.5C : 4000 Cycles
Claimed Cycle Life @ 1C : 4000 Cycles
Production technology – Winding
LF280
The EVE LF280 has a cycle life of 4000 cycles at 0.5C/0.5C. Giving it an estimated lifespan of up to 11 years Capacity: 280Ah Nominal Voltage: 3.2V
LIFEPO4 AUSTRALIA OPINION Cycle Life @ 1C : 2000 Cycles Cycle Life @ 0.5C : 4000 Cycles
Maximum Continuous Discharge 1C Production technology – Winding
LF280K
EVE LF280K
The EVE LF280K has a cycle life of 6000 cycles at 0.5C/0.5C. Giving it an estimated lifespan of up to 16 years Capacity: 280Ah Nominal Voltage: 3.2V
LIFEPO4 AUSTRALIA OPINION Cycle Life @ 1C : 3000 Cycles
Cycle Life @ 0.5C : 6000 Cycles Production technology – Winding
LF280k v3
The EVE LF280K has a cycle life of 6000 cycles (A+ Grade 8000 Cycles) at 0.5C/0.5C. Giving it an estimated lifespan of up to 16 years Capacity: 280Ah Nominal Voltage: 3.2V
LIFEPO4 AUSTRALIA OPINION Cycle Life @ 1C : 4000 Cycles Cycle Life @ 0.5C : 8000 Cycles
The EVE MB30 has a cycle life of 10000 cycles at 0.5C/0.5C. Giving it an estimated lifespan of up to 20-25 years Capacity: 306Ah Expected Real measured capacity when new 320+AH Nominal Voltage: 3.2V
LIFEPO4 AUSTRALIA OPINION @ Thermally controlled environment Cycle Life @ 1C : 5000 Cycles Cycle Life @ 0.5C : 10000 Cycles
The EVE MB31 has a cycle life of 8000 cycles at 0.5C/0.5C. Giving it an estimated lifespan of up to 20-25 years Capacity: 314Ah Expected Real measured capacity when new 330+AH Nominal Voltage: 3.2V Advertised Cycle Life: 8000 Cycles
LIFEPO4 AUSTRALIA OPINION @ Thermally controlled environment Cycle Life @ 1C : 4000 Cycles Cycle Life @ 0.5C : 8000 cycles
Maximum Continuous Discharge 1C Recommended Discharge 0.5C
Production technology – Stacking
Stacking vs Winding
Longer life span The stacked battery cell has more tabs, the shorter the electron transmission distance, and the smaller the resistance, so the internal resistance of the stacked battery cell can be reduced, and the heat generated by the battery cell is small. The winding is prone to deformation, expansion and other problems, which affect the attenuation performance of the battery.
Comparing process of stacking battery vs winding
Stacking
Winding
Energy density
Higher. Higher space utilization.
Lower. There is a C angle, and the larger the capacity, the lower the utilization rate.
Structural stability
Higher. The internal structure is uniform and the reaction rate is relatively low.
Lower. There is a C angle, which leads to uneven rate of internal reaction of charging and discharging.
Fast charging adaptation
Better. The multi-pole plates are connected in parallel, the internal resistance is low, and the charge and discharge of large current can be completed in a short time, and the rate performance of the battery is high.
Poor. During the charge and discharge process, the degradation rate of the active material at the high temperature position is accelerated, and the other positions are rapidly attenuated.
Safety
The risk is low. Stress distribution is more consistent, which keeps the interface flat and more stable.
Lower. Potential problems such as powder shedding, burrs, pole piece expansion, and separator stretching are easy to occur at the bend.
Cycle life
Longer. Low internal resistance, relieve battery heating during fast charging, improve battery chemical system stability and prolong service life.
Shorter. It is easy to deform in the later stage, which in turn affects the cycle life of the battery.
Productivity
Large-capacity batteries are generally low, mainly 6-8PPM.
Higher, generally at 12-13PPM.
Yield
Low, the glitch problem is prominent.
Higher automation, higher yield rate, higher number of pole pieces.
Process maturity
Low, the number of pole pieces is large, and the investment in equipment is large.
Higher, fewer pole pieces, mature equipment and low investment cost.
Summary of new technology
Technologies such as low-expansion anode materials, full tab design, electrode surface treatment, and flexible electrode forming help resolve liquid infiltration challenges for large cells, enabling comprehensive safety protection and high cycle life through heat insulation, diffusion prevention, pressure relief
What to choose for a battery with the longest lifespan.
EVE MB30 Automotive A+ verified cells directly supplied from EVE, not via a third party, not via Alibaba, and not from most resellers and battery pack manufacturers including almost all battery builders in Australia and China, unless they can provide you with a) the official eve delivery report for the cell purchase, and b) evidence that the QR code is genuine and not re-lasered. The B grade to A grade problem is going to be larger with the new models the LF280K v3 which is actually the MB30
A genuine QR code should be shiny behind the data that has been printed.
We can supply a range of CATL EnerOne storage systems. Are you looking for a commercial grade energy storage solution?
Contact us for pricing and availability, Generally a lead time of about 90-120 days is required for CATL to be able to supply these kinds of systems.
Having modular nominal capacity of 232.96Kw, 372.7 kWh and 407.34kWh depending on the cell chosen, 280, 285 and 306ah with a floor space of just 1.69 square meters. The system is suitable for inverters with operating voltages ranging from 600 to 1500 volts. EnerOne can be efficiently shipped as a complete product, which greatly reduces on-site installation costs and commissioning time.
EnerOne can be used flexibly in outdoor applications, thanks to the protection level IP 66 of the main components and the adaptability to ambient temperature range of -30 to +55 ℃. It has passed various critical tests on the cell, module and rack level. EnerOne has obtained UL9540A test report, and in this test there’s no fire and no extra thermal propagation without the help from fire suppression system.
High level of safety
LFP batteries with high thermal stability
Protection level of IP66 to meet the requirements of outdoor applications
Resistance up to C5 corrosion level, with 20-year reliability
Separate fire protection system
Long service life
Available for integration with CATL’s advanced technologies (e.g. optional cell with super-long cycling up to 12,000 cycles)
Integrated frequency conversion liquid-cooling system, with cell temperature difference limited to 3ºC, and a 33% increase of life expectancy
High integration
Modular design, compatible with 600 – 1,500V system
Separate water cooling system for worry-free cooling
Modular design with a high energy density, saving the floor space by 50%
Transportation after assembly, reducing on-site installation costs and commissioning time
The EnerOne+Rackconsists of following parts: batteries, BMS, FSS and TMS, which are integrated together to keep the normal working of the Rack.
Battery
The capacity of cellis 306Ah,1P52S cells integrated in one module,8 modules integrated into one Rack.As the core of the energy storage system, the battery releases and stores energy.
BMS
BMSadopts the distributed scheme, through the three-level (CSC–SBMU–MBMU)architecture to control the BESS,andensure the stable operation of the energy storage system.It canmanageenergy absorption and release, the thermal management system andauxiliarypower supplyaccording to the detectedinformation:battery voltage, currentandtemperature.It canmonitorhigh voltage DC/AC security, diagnosis and analysis faultsaccording informationfrom various detectors and dry-contacts.Andit cankeep communicationwith PCS and EMSthrough CAN.
FSS
FSS consists of smoke detectorand heatdetector(Orheatdetector and gasdetector), the aerosol, the dry pipe(optional).FSSundertakesfunctions :monitorthe thermalrun-awayrisks ofRackthroughthedetectors, extinguishthe thermal run awayin an early stage, andcontrol the loss to minimum. The FSS is independent with any other systemandit is the security guard of EnerOne+Rack.
TMS
TMS consists of one powerful chiller, one PTC heaterandthe liquid cooling pipe distributed in each battery module. The TMS will keep the battery work at best state and reach longest life.
Controlbox
Control box mainly includes detection device, protection device and AC/DC power supply. The structure is shown as follows.
Energy storage cells can store electrical energy and release it when needed, such as during peak demand or power outages. They can also help balance the grid, reduce carbon emissions, and increase energy efficiency. Energy storage cells have various applications, such as home energy storage, grid-scale energy storage, electric vehicles, and portable devices.
Let’s dive into these four topics and see how they will ensure LiFePo4 and other relevant battery storage chemistries, will become increasingly more affordable on a TCO basis.
Increased capacity, competition in mass production
One of the main challenges for energy storage cells is to increase their capacity, which means the amount of energy they can store per unit volume or weight. Higher capacity means higher energy density, which can reduce the cost and space requirements of energy storage systems. Higher capacity also means longer duration, which can extend the operating time of energy storage systems.
Many energy storage cell manufacturers have been developing and releasing high-capacity products in recent years, especially in the lithium-ion battery sector. For example, EVE has released information about the upcoming LF560K energy storage battery. The battery capacity is at least 560Ah (reported to be as high as 628ah), twice that of LF280K, and the energy of a single battery reaches 1.792kWh (reportedly 2000wh, also known as 2kwh per cell)
LF560K-560k-EVE-LFP-Lifepo4
winston-wb-lyp700aha-lifeypo4
We should quickly mention that Winston Thundersky has been producing larger format cells such as the 700ah, 1000ah and 10000ah for a long time, but the competitiveness in terms of price and weight is being left for dead by the new generation of LFP manufacturers such as CATL, BYD, GOTION, EVE, HITHIUM, Envision AESC, Great Power, REPT, Narada and energy storage battery cell companies have successively released 300Ah and above capacity battery products . While the capacity is increasing, mass production and delivery of 300Ah and above capacity batteries have also started. It is worth mentioning that Envision AESC has achieved mass production and delivery of 305Ah energy storage cells in the past two years, and recently released 315Ah energy storage cells within the same size and format.
Right now in 2024, the 173 x 73 x 207 mm battery is the most popular for DIY because it has the best cost per kwh. Due to the competition in this area. In late 2023, Envision lead the pack with pricing that was about 50% of the going prices from 2021-2023.
Mass production and delivery of high-capacity batteries can create economies of scale and reduce the cost per kWh of energy storage systems. It can also increase the competitiveness of energy storage cell manufacturers in the global market and meet the growing demand for large-scale energy storage projects.
Energy storage cell stacking vs winding comparison
Another challenge for energy storage cells is to optimize their structure and manufacturing process to improve their performance and reliability. One of the key factors that affect the structure and process of energy storage cells is whether they use stacking or winding methods to arrange the electrodes and separators inside the cell.
Stacking is a method that stacks the positive and negative electrodes and separators layer by layer to form a cell. Winding is a method that winds the positive and negative electrodes and separators into a spiral shape to form a cell. Both methods have their advantages and disadvantages.
Stacking can achieve higher packing density and higher capacity than winding, but it requires more precise alignment and cutting of electrodes and separators, which increases the complexity and cost of manufacturing. Winding can achieve better uniformity and consistency than stacking, but it may cause more internal resistance and heat generation, which reduces the efficiency and safety of the cell.
Different manufacturers may choose different methods according to their own technical advantages and market positioning. For example, EVE uses stacking for its LF560K battery, while Envision AESC uses winding for its 315Ah battery . The choice of stacking or winding may also depend on the shape and size of the cell, which we will discuss next.
Longer cycle life
The number of lugs of stacking batteries is twice that of winding, and the more the tabs, the shorter the electron transmission distance and the smaller the resistance.
It is well known that when the voltage and time are constant, the larger the resistance, the less heat generated, and the smaller the resistance, the smaller the heat generated, so the service life of stacking batteries is relatively longer than winding batteries to compare stacking battery vs winding battery. This is the main reason we have seen cell life increase from 2000 cycles to 12000 cycles. These numbers are in ideal conditions, which almost certainly are unachievable in almost all DIY battery projects.
Stacking battery has a Lower yield rate, which is why there are so many B grade cells for sale
The winding battery is easy to cut and has a high pass rate. Each battery cell only needs to cut the positive and negative electrodes once, which is less difficult. However, compared stacking battery vs winding, each battery has dozens of small pieces in stacking cutting, and each small piece has four cut surfaces, which is prone to defective products.
A recent industry leak stated “the iPhone 15 line arriving in the coming months would be equipped with batteries with stacked structure. In standard ones, the three main elements (anode, cathode and separator) are three thin sheets rolled up on top of each other. In this type of battery, however, the separator is folded in a zigzag and takes up less space in the battery, and therefore there is more space for increase its capacity due to higher energy density. Furthermore, this type of arrangement ensures that the temperatures are dissipated more evenly, avoiding concentrating them in a single space and prolonging their longevity”.
The size of energy storage cells
The size of energy storage cells is another important factor that affects their performance and application. The size of a cell determines its volume, weight, surface area, heat dissipation, internal resistance, power density, etc. Generally speaking, larger cells have higher capacity but lower power density than smaller cells. Larger cells also have more challenges in heat management and safety than smaller cells.
The size of energy storage cells can be measured by their diameter and height (for cylindrical cells) or length and width (for prismatic or pouch cells). The common sizes for lithium-ion batteries range from 18650 (18mm diameter x 65mm height) to 21700 (21mm diameter x 70mm height) for cylindrical cells, and from 20Ah to 560Ah for prismatic or pouch cells.
Different sizes of cells may suit different applications of energy storage systems. For example, smaller cells may be more suitable for portable devices or electric vehicles that require high power density and fast charging/discharging. Larger cells may be more suitable for home energy storage or grid-scale energy storage that require high capacity and long duration.
The size of energy storage cells may also change with the development of technology and market demand. For example, some manufacturers are developing solid-state batteries that can achieve higher energy density and safety than liquid or gel electrolyte batteries, which may enable smaller and lighter cells . Some manufacturers are also developing modular and scalable energy storage systems that can use different sizes of cells according to the needs of customers .
Industry calls for long cycle of battery cells
The last trend we will discuss is the demand for long cycle life of energy storage cells. Cycle life is the number of times a cell can be charged and discharged before its capacity drops below a certain threshold (usually 80% of its initial capacity). Cycle life is an important indicator of the durability and cost-effectiveness of energy storage cells.
Long cycle life can extend the lifespan of energy storage systems and reduce the need for replacement or maintenance. Long cycle life can also reduce the environmental impact of energy storage systems by reducing the waste and emissions generated by cell production and disposal. Long cycle life can also increase the value of energy storage systems by enabling more applications and services, such as frequency regulation, peak shaving, demand response, etc.
The cycle life of energy storage cells depends on many factors, such as the chemistry, structure, process, operation, and management of the cells. Different types of cells may have different cycle life characteristics. For example, lithium iron phosphate (LFP) batteries have longer cycle life than lithium nickel manganese cobalt oxide (NMC) batteries, but lower energy density . Different applications of energy storage systems may also have different cycle life requirements. For example, home energy storage may require longer cycle life than electric vehicles, because home energy storage may operate more frequently and continuously than electric vehicles.
Many energy storage cell manufacturers have been improving their cycle life performance by optimizing their materials, designs, processes, and systems. For example, Envision AESC claims that its 315Ah battery can achieve more than 10,000 cycles at 80% depth of discharge (DOD) . TYCORUN ENERGY claims that its home energy storage products use lithium iron phosphate batteries, which have a deep cycle of more than 6000 times with low self-discharge rate .
Conclusion
In summary, we have discussed four trends in the development of energy storage cells: increased capacity, competition in mass production; energy storage cell stacking vs winding comparison; discussion on the size of energy storage cells; economy calls for long cycle of battery cells. These trends reflect the technological innovation and market demand in the energy storage industry, which is expected to grow rapidly in the coming years. Energy storage cells are key components for renewable energy systems, which can provide clean, reliable, and affordable electricity for various applications.
We hope this blog post has given you some insights into the current state and future direction of energy storage cells. If you are interested in learning more about energy storage products and solutions, please visit our website or contact us for more information.
Here is a nice professional production video by EVE Energy. Footage is taken about 18 months ago. In their most advanced factory, which produces LF280K
What are the most common curves for circuit breakers that are DC rated to 250A?
If you are looking for a circuit breaker that can handle direct current (DC) loads up to 500A, you might wonder what kind of tripping curve you should choose. A tripping curve is a graphical representation of how fast a circuit breaker will trip in response to different levels of overcurrent. It shows the relationship between the current and the tripping time of a protection device.
There are different types of tripping curves for circuit breakers, such as B, C, D, K and Z. Each curve has a different instantaneous trip current range, which is the amount of current at which the breaker will trip without causing a time delay. Generally, the higher the current spike, the faster the breaker will trip.
The most common curves for circuit breakers that are DC rated to 500A are C and D curves. These curves are suitable for inductive and motor loads with medium to high starting currents. They can also handle the inrush current of DC loads, which is the high current draw during the switching on of a load.
A C curve circuit breaker will trip instantaneously when the current flowing through it reaches between 5 to 10 times the rated current. For example, a C curve circuit breaker with a rated current of 25A will trip between 125A and 250A without any delay. This type of curve is ideal for domestic and residential applications and electromagnetic starting loads with medium starting currents.
A D curve circuit breaker will trip instantaneously when the current flowing through it reaches between above 10 (excluding 10) to 20 times the rated current. For example, a D curve circuit breaker with a rated current of 25A will trip between above 250A (excluding 250A) and 500A without any delay. This type of curve is ideal for inductive and motor loads with high starting currents.
The other curves, such as B, K and Z, are less common for circuit breakers that are DC rated to 250A. These curves are either too sensitive or too insensitive to short circuits and are used for specific applications.
A B curve circuit breaker will trip instantaneously when the current flowing through it reaches between 3 to 5 times the rated current. This type of curve is too sensitive for DC loads with high inrush currents and is mainly used for cable protection and electronic devices with low surge levels.
A K curve circuit breaker will trip instantaneously when the current flowing through it reaches between 8 to 12 times the rated current. This type of curve is similar to a D curve but has a higher instantaneous trip range. It is used for inductive and motor loads with very high inrush currents.
A Z curve circuit breaker will trip instantaneously when the current flowing through it reaches between 2 to 3 times the rated current. This type of curve is too insensitive for DC loads with high inrush currents and is mainly used for highly sensitive devices such as semiconductor devices.
To summarize, the most common curves for circuit breakers that are DC rated to 250A are C and D curves, depending on the type and size of the load. These curves can provide adequate protection against overcurrents and short circuits without tripping unnecessarily or too slowly.
An Alternative is to use a Circuit Breaker is a T class fuse
If you are using lithium batteries in any application, you might want to consider using a T-class fuse as part of your safety measures. A T-class fuse is a type of fuse that is specifically designed for use with lithium batteries. It has a fast-acting, low-melting-point element that can quickly interrupt the flow of current in the event of an overcurrent or short-circuit condition. This helps prevent damage to the battery and reduces the risk of fire or explosion.
Here are some of the benefits of using a T-class fuse in your lithium battery setup:
Improved Safety: T-class fuses can protect the battery from overcurrent and short-circuit conditions, which can help prevent damage to the battery and reduce the risk of fire or explosion .
Increased Reliability: T-class fuses can help increase the overall reliability of your setup by preventing damage to the battery and other components in case of an overcurrent or short-circuit condition . This is especially important in applications where downtime or failure can be costly or dangerous.
Simplified Design: T-class fuses can simplify the design of your lithium battery setup by eliminating the need to select the right type of fuse for your application. Because they are designed specifically for use with lithium batteries, you don’t have to worry about compatibility issues or errors .
Cost-Effective: T-class fuses are generally affordable, especially when compared to the cost of replacing damaged batteries or dealing with the consequences of a battery-related incident. They are also durable and long-lasting, which can save you money in the long run .
To sum up, using a T-class fuse in your lithium battery setup can provide a range of benefits, from improved safety and reliability to simplified design and cost savings. If you want to learn more about T-class fuses and how to use them, you can read more, to learn about
Class T vs ANL fuse
Choosing between ANL and Class T fuses depends on your specific needs and application. Here’s a breakdown of their key differences to help you decide:
Current Interrupt Capacity:
ANL fuse: Up to 2,700 amps, suitable for automotive starting batteries and modest DC current applications.
Class T fuse: Up to 200,000 amps, significantly higher, making it ideal for high-power systems with lithium batteries, solar panels, inverters, etc.
Response Time:
ANL fuse: Moderately fast, but not as fast as Class T.
Class T fuse: Very fast, crucial for protecting sensitive electronics from quick surge currents.
Size and Cost:
ANL fuse: Larger and typically cheaper.
Class T fuse: Smaller and more expensive due to its superior capabilities.
Applications:
ANL fuse: Good for:
Starter batteries
Audio systems
Winches
Moderate-power DC circuits
Class T fuse: Ideal for:
Lithium batteries
Solar power systems
Inverters
High-power industrial applications
Sensitive electronics requiring fast protection
Additional Considerations:
ANL fuses: Prone to arcing after blowing, potentially causing further damage.
Class T fuses: Designed to minimize arcing, enhancing safety.
Certification: Class T fuses often have UL 248-15 listing, important for marine applications.
In summary:
Choose ANL fuse for moderate-power DC applications like car audio or winches where affordability is a concern.
Choose Class T fuse for high-power systems with lithium batteries, solar panels, or sensitive electronics where fast response and high interrupt capacity are critical, despite the higher cost.
Class-T fuses
are a type of high-performance, fast-acting fuse designed for protecting demanding electrical systems from damage caused by overcurrents and short circuits. They are known for their:
High interrupt capacity: Up to 200,000 amps, making them suitable for high-power applications like marine, solar, and industrial systems.
Fast response time: They blow very quickly in the event of a fault, minimizing damage to equipment.
Compact size: They are smaller than other types of fuses with similar current ratings, making them ideal for space-constrained applications.
Corrosion resistance: They are constructed with nickel-plated terminals and a sealed ceramic body, making them resistant to corrosion in harsh environments.
Here are some of the common applications of Class-T fuses:
Marine electrical systems: Protecting batteries, inverters, chargers, and other sensitive equipment. Class T fuse in marine electrical system
Solar power systems: Protecting solar panels, charge controllers, and batteries. Class T fuse in solar power system
Industrial control panels: Protecting motors, drives, and other critical equipment.
Battery banks: Protecting large battery banks from short circuits and overcurrent’s. Class T fuse in battery bank
Variable speed drives: Protecting drives from motor faults and overloads.
Rectifiers: Protecting rectifiers from overloads and short circuits.
When choosing a Class-T fuse, it is important to consider the following factors:
The amount of current the circuit will carry: Choose a fuse with a current rating that is slightly higher than the maximum expected current in the circuit.
The type of fault the fuse is protecting against: Choose a fuse with an interrupt capacity that is high enough to handle the maximum fault current that is likely to occur.
The physical size constraints of the application: Choose a fuse that will fit in the available space.
I cannot directly recommend a specific fuse size without more information. Choosing the wrong fuse size can be dangerous, so it’s crucial to follow proper guidelines and consult a qualified electrician for accurate sizing.
However, I can help you gather the necessary information to make an informed decision:
1. Identify your application:
What are you protecting with the fuse (e.g., battery bank, inverter, solar panel system)?
What is the voltage and amperage rating of the circuit?
2. Consult the device manuals:
The manuals for your devices (battery, inverter, etc.) should specify the recommended fuse size or amp rating.
Do not exceed the recommended fuse size for any device.
3. Consider continuous and surge currents:
Choose a fuse with a continuous current rating slightly higher than the maximum expected current in the circuit under normal operation.
Account for potential surge currents (e.g., motor startup) and choose a fuse with an interrupt capacity high enough to handle those surges safely.
4. Follow safety standards and regulations:
Ensure the chosen fuse complies with relevant safety standards for your application (e.g., UL 248-15 for marine use).
5. Consult a qualified electrician:
If you’re unsure about any aspect of fuse selection or electrical work, always seek guidance from a qualified electrician. They can assess your specific needs and recommend the most suitable fuse size for your application, ensuring safety and optimal performance.
Remember, safety is paramount when working with electrical systems. Never experiment with fuse sizes or attempt electrical work without proper knowledge and qualifications.
Class-T fuses are a reliable and effective way to protect your electrical equipment from damage. If you are unsure about which fuse to choose, consult with a qualified electrician.
Remember, consult qualified personnel when dealing with high-power applications and fuse selection. They can assess your specific needs and recommend the most suitable option for safety and optimal performance.
We hope this blog post was informative and helpful for you. If you have any questions or feedback, please feel free to leave a comment below. Thank you for reading!
X
Your amount to pay has been updated
The previous conversion quote has expired. Here is your new quote:
