VRLA Research Articles

Design of the VRLA Battery Real-Time Monitoring System Based on Wireless Communication.

The VRLA (valve-regulated lead-acid) battery is an important part of a direct current (DC) power system. In order to resolve issues of large volume, complicated wiring, and single function for a battery monitoring system at present, we propose to build a novel intelligent-health-monitoring system. The system is based on the ZigBee wireless communication module for collecting voltage, temperature, internal resistance, and battery current in real-time. A general packet radio service (GPRS) network is employed for interacting data with the cloud-monitoring platform. The system can predict the remaining capacity of the battery combined with the software algorithm for realizing real-time monitoring of the battery’s health status and fault-warning, providing a basis for ensuring the safe and reliable operation of the battery. In addition, the system effectively integrates most of the circuits of the battery status collector onto one chip, which greatly reduces the size and the power consumption of the collector and also provides a possibility for embedding each VRLA battery with a chip that can monitor the health status during the whole life. The test results indicate that the system has the characteristics of real-time monitoring, high precision, small-volume, and comprehensive functions.

Estimating the Cost of Point-of-Care Early Infant Diagnosis in a Program Setting: A Case Study Using Abbott m-PIMA and Cepheid GeneXpert IV in Zimbabwe.

Point-of-care early infant diagnosis (POC EID) increases access to HIV test results and shortens time to result-return and antiretroviral therapy initiation, as compared to central laboratory-based EID. However, to scale-up POC EID, governments need more information about programmatic costs. We evaluated POC EID costs from a health systems perspective. Our primary analysis assessed the Abbott m-PIMA and 2 versions of the Cepheid GeneXpert IV platforms-with a solar battery or gel battery-used in Zimbabwe, with instrument purchase. We also included the following 2 scenarios with zero upfront equipment purchase: (1) m-PIMA using a reagent rental model, with an all-inclusive price when the buyer commits to an average testing volume, and (2) GeneXpert IV, reflecting contexts where GeneXpert is already in place for tuberculosis diagnosis or HIV viral load monitoring. We collected data from project expenditures, observations of health workers, and from government salary scales. We calculated cost per EID test based on number of EID tests performed on each machine per day. The cost per successfully completed test was $44.55 for m-PIMA with platform purchase and $25.89 for m-PIMA reagent rental. Costs for GeneXpert IV with platform purchase were $25.70 using a solar battery, $25.29 using a gel battery, and $23.85 under a scenario assuming no equipment costs. In our primary analyses, materials costs comprised 73%-74% total costs, equipment 14%-20%, labor 5%-8%, training 1%, facility upgrades 1%, and monitoring 1%. As countries consider scaling up POC EID, these data are important for budgeting and planning.

Trade-off between end of life of battery and reliability in a photovoltaic system

For the sustainable future of a microgrid with energy storage, the important criterion to its consumers are affordability and reliability of power supply. In a photovoltaic (PV) battery microgrid, the battery life is a critical factor as it directly correlates with the life cycle cost of the system. The battery lifetime given by the manufacturer is limited only to ideal conditions. In practical contexts, these vary and are closely dependent on operating and ambient conditions. In addition, battery manufacturers specify their End of Life (EoL) condition at 80% of rated capacity (i.e., 20% battery degradation). There exists a trade-off between cost and reliability, when the end of life of the battery is extended beyond the manufacturer specifications. This paper models this trade-off and calculates battery degradation rates in a microgrid, which can be utilised in refurbishing the optimal design solution of the system. The PV battery microgrid along with the capacity fade of the battery is modelled for Indian contexts. The solar irradiance and the ambient temperature of five different climatic zones of India along with the synthetic load of a hamlet with twenty households are given as inputs and its battery degradation rates are computed. The system is further simulated beyond the battery EoL by considering both PV and battery degradation to evaluate the trade-off between cost and reliability. The results indicate that the end of life condition of battery should be selected based on acceptable levels of reliability. As an example, for a 2 V, 500Ah valve-regulated lead-acid (VRLA) battery with a rated service life of 10 years (80% end of life and 25 °C) will last only 4.8 years in the hot and dry climate of Jodhpur, India when the continuous capacity fade is considered. If the acceptable reliability levels are at 3%, then the battery will last for eight years with an end of life condition at 66% of the initial capacity. As a result, the life cycle cost of the system reduces from 26.5 to 20.6 ₹/kWh.

Valve regulated lead acid battery diagnostic system based on infrared thermal imaging and fuzzy algorithm

In recent times, advanced inspection technique like infrared thermography (IRT) has been used widely for fault diagnosis of electrical equipment in non-contact, non-destructive and non-invasive manner. Manual classification of faults from the IRT images requires more time and effort. In this work, an intelligent scheme for predictive fault diagnosis in VRLA battery is presented for scheduling its preventive maintenance. IR images of pristine and aged VRLA battery in uninterrupted power supply application are acquired using IR camera at different discharging cycles. Image processing of IR images is performed for detection of faults. In order to intelligently classify the faults a fuzzy inference system is developed. Proposed scheme for automatic diagnosis and classification of faults in VRLA battery is implemented using LabVIEW 2015 software. The output information defining the condition of VRLA battery is displayed on front panel of LabVIEW and stored in MS Excel file with the time stamp at hard disk of host computer for further reliability analysis. Based on occurrence of major faults in VRLA battery, alert signal is send to intended users at both onsite and remote locations. To facilitate remote condition monitoring of VRLA battery, front panel information is continuously provided to remote user using web publishing tool of LabVIEW. Using proposed technique, the fault diagnosis of lead acid batteries in different battery applications can similarly be performed in non-invasive manner.

Simple and effective modification of absorbed glass mat separator through atmospheric plasma treatment for practical use in AGM lead-acid battery applications

Simple and effective modification method of commercial AGM using atmospheric plasma etching was reported for practical use in AGM battery applications. In order to enhance electrical performance and durability by improving degree of absorption of AGM for electrolyte solution, plasma-treated AGMs, AGM-X-Y, were fabricated by adjusting RF power and treatment time. In general, BET surface area and the degree of adsorption for electrolyte solution of plasma-treated AGMs increased with increase of RF power and plasma treatment time. However, on the contrary, too high RF power and long treatment time disturbed improvement of various properties, which would stem from smoothing of fiber surface and hydrophobic change by etching gas. The AGM-200-10 separator, which was treated with RF power of 200 W for 10 min, showed outstanding BET specific surface area (1.96 m2/g) and adsorption property (1.27 g/cc) for electrolyte. Moreover, AGM battery single cell with the AGM-200-10 separator showed much better electrical performance and durability in charge-discharge operation test under accelerated conditions, which should indicate the feasibility of the AGM-200-10 separator for practical use.

Discussion of the relationship between failure and fire of valve regulated lead acid battery

Failure modes of the valve regulated lead acid battery will not only greatly reduce the service life, but also may start a fire. This paper reviews the relationship between battery fire and failure modes. Four failure modes influenced on the valve regulated lead acid battery were emphatically analyzed: “Sulfation of negative electrode plate”, “corrosion of the positive electrode plate”, “loss of water” and “acid leak”. The direct reasons for battery fire are thermal runaway, short circuit and hydrogen explosion, which were inducing by battery failure. A fire prevention scheme was proposed on the basis of above thesis.

Эффективность ионизации кислорода в макете свинцово-кислотного аккумулятора с использованием сепаратора из абсорбтивно-стеклянной матрицы и нетканого волокнистого материала на основе поливинилиденфторида и полистирола

Эффективность ионизации кислорода в макете свинцово-кислотного аккумулятора с использованием сепаратора из абсорбтивно-стеклянной матрицы и нетканого волокнистого материала на основе поливинилиденфторида и полистирола

Thermal Management of Li-Ion Batteries With Single-Phase Liquid Immersion Cooling

Development of effective thermal management techniques is essential in enabling further technical advances and wide public acceptance of lithium-ion based battery electrical storage. Both stationary battery arrays and electric vehicle (EV) batteries are pressed to enable charging and discharging at faster C rates, increased amp-hour capacity, longer service life and increased safety. All of these are dependent on more efficient and safer thermal management solutions. Traditional air cooling and indirect liquid cooling (cold plate) methods have limitations in effectiveness and weight. Engineered Fluids has recently completed a series of experiments demonstrating the high efficiency of Single-phase Liquid Immersion Cooling (SLIC) technology for the thermal management of Li-ion batteries. This article reviews the results of these experiments and discusses some of the issues and solutions for battery thermal management, and outlines the proper design of battery thermal management systems. We will discuss such topics as active cooling versus passive cooling, liquid cooling versus air cooling, cooling and heating versus cooling only systems, and relative needs of thermal management for VRLA, NiMH, and Li-Ion batteries.

Predictive Maintenance of VRLA Batteries in UPS towards Reliable Data Centers

The reliability of data centers can be severely affected when battery failure occurs in the Uninterruptible Power Supply (UPS). Thus it has become a central issue for the industry to discover failure-impending batteries in UPS. In this paper, we consider this important problem and present a data-driven method for predictive battery maintenance. The major contributions are as follows.First, we develop a changepoint detection technique for efficient data labeling. Second, new features are designed to fully utilize the dataset. Third, we build a predictive classification model which can discriminate between healthy and failure-impending batteries. Our method has been built and evaluated on 209,912,615 records from Tencent data center involving nearly 300 batteries monitored over 2 years. The experiment on test set shows that our method is able to predict battery replacement with 98% accuracy and averagely 15 days in advance, which outperforms the previous maintenance policy by more than 8%.

Pyrite-type cobalt phosphosulphide bifunctional catalyst for aqueous and gel-based rechargeable zinc-air batteries

Bifunctional electrocatalysts with favorable electrode kinetics towards oxygen reduction and oxygen evolution reactions are the main pre-requisites to achieve practical utility of metal-air systems. Herein, ternary pyrite type nanosized cobalt phosphosulphide is reported as an excellent oxygen reduction/oxygen evolution catalyst in alkaline medium with a favorable reversible oxygen electrode index (difference between E10mA for oxygen evolution and E3mA for oxygen reduction) of 0.69 V. Four-electron reduction with low overpotential of ~240 mV to observe a current density of 10 mA cm−2 is reported. The assembled zinc-air batteries with both aqueous liquid- and gel-based electrolytes display stable low charge-discharge voltage polarization over a long duration. Aqueous primary zinc-air battery exhibits an impressive peak power density of 385 mW cm−2 at 560 mA cm−2 and a current density of 220 mA cm−2 at 1.0 V. The zinc-air battery in the air-breathing, rechargeable mode operates for over 100 h at 10 mA cm−2 and over a few hundred cycles under a drain current of 50 mAcm−2. The rechargeable battery has been investigated for both long term (4 h) and short term (10 min) cycles under different drain currents (10, 20 and 50 mA cm−2). Round trip efficiencies of ~64% have been achieved. Use of CoPS electrodes with gel-based electrolytes has also been demonstrated. The primary gel battery displays a specific capacity of 803 mA cm−2 corresponding to an energy density of 891 Wh kg−1. The high efficiency and durability of the catalyst establish its feasibility as a cost-effective alternative to precious metal catalysts.

Flexible and rechargeable electrochromic aluminium-ion battery based on tungsten oxide film electrode

Electrochromic (EC) energy storage devices that possess characteristics of energy storage and electrochromism are highly desirable and have increasingly attracted research interests, whilst devices that can be stretched or are flexible have received very little attention. Herein, we report a flexible and rechargeable aluminium (Al) ion EC battery (ECB), which consists of a WO3 film as positive electrode, PET/ITO as substrate, Al sheet as negative electrode, aluminum trichloride (AlCl3) aqueous solution as electrolyte, and absorptive glass mat (AGM) as electrolyte carrier and separator. The ECB exhibits a high specific capacity of 142 mAhg−1, while demonstrating reversible color transitions between white (bleached state) and dark blue (colored state) during the cyclic charge/discharge processes. Furthermore, the ECB can work at bending angles of 0-80° with a capacity retention of 92.3% after 40 bending cycles. The flexibility of the ECB is ascribed to the flexible, porous, and highly stable features of the AGM as well as the deformability of the PET/ITO substrate. The potential widow of the ECB can be largely enhanced by connecting small-sized ECBs internally in series while maintaining the energy density unchanged. The present study demonstrates that the ECB using the AGM as the electrolyte carrier and separator may have great potentials for the construction of both flexible, portable electronics and smart windows.

Probing the three-dimensional porous and tortuous nature of absorptive glass mat (AGM) separators

Abstract The valve regulated lead acid (VRLA) battery is a predominant electrochemical storage system that stores energy in a cheap, reliable and recyclable manner for innumerable applications. The absorptive glass mat (AGM) separator is a key component, which is pivotal for the successful functioning of the VRLA battery. Herein, the intricate three-dimensional (3D) porous structure of AGM separators has been unveiled using X-ray micro-computed tomography (microCT) analysis. X-ray microCT has quantified a variety of fiber and structural parameters including fiber orientation, porosity, tortuosity, pore size distribution, pore interconnectivity and pore volume distribution. A predictive model of hydraulic tortuosity has been developed based upon some of these fiber and structural parameters. Moreover, the pore size distribution extracted via X-ray microCT analysis has served as a benchmark for making a comparison with the existing analytical model of the pore size distribution of AGM separators. Pore size distributions obtained via the existing analytical model and through X-ray microCT analysis are in close agreement.

Aging and performance comparison of absorbed glass matte, enhanced flooded, PbC, NiZn, and LiFePO4 12V start stop vehicle batteries

Engine start-stop systems have been widely adopted for internal combustion engine passenger vehicles, with low voltage 12 V systems currently capturing most of the market. While absorbed glass mat (AGM) lead-acid batteries are commonly used for this application, there is interest in other battery types to reduce cost or improve performance. This work examines a range of battery types and compares experimentally determined performance and aging characteristics. Six different start/stop batteries are tested, including two AGM, an enhanced flooded lead acid (EFB), lead carbon (PbC), nickel zinc (NiZn), and LiFePO4 battery. The batteries are aged with a series of start-stop microcycles, which consist of an accessory power and engine-starting discharge pulse followed by a charging pulse. Thirty thousand microcycles correlate with the conditions a start-stop battery would be exposed to over approximately 160,000 km of driving in a typical North American application. The testing procedure begins with two characterization tests - a capacity and HPPC charge and discharge resistance test - and is followed by 3,000 microcycles to age the battery. Characterization and aging tests are repeated until the battery is no longer able to perform the microcycles, and substantially different aging and performance characteristics are observed for each battery.

Marine NMEA 2000 Smart Sensors for Ship Batteries Supervision and Predictive Fault Diagnosis.

In this paper, an application for the management, supervision and failure forecast of a ship’s energy storage system is developed through a National Marine Electronics Association (NMEA) 2000 smart sensor network. Here, the NMEA 2000 network sensor devices for the measurement and supervision of the parameters inherent to energy storage and energy supply are reviewed. The importance of energy storage systems in ships, the causes and models of battery aging, types of failures, and predictive diagnosis techniques for valve-regulated lead-acid (VRLA) batteries used for assisted and safe navigation are discussed. In ships, battery banks are installed in chambers that normally do not have temperature regulation and therefore are significantly conditioned by the outside temperature. A specific method based on the analysis of the time-series data of random and seasonal factors is proposed for the comparative trend analyses of both the battery internal temperature and the battery installation chamber temperature. The objective is to apply predictive fault diagnosis to detect any undesirable increase in battery temperature using prior indicators of heat dissipation process failure—to avoid the development of the most frequent and dangerous failure modes of VRLA batteries such as dry out and thermal runaway. It is concluded that these failure modes can be conveniently diagnosed by easily recognized patterns, obtained by performing comparative trend analyses to the variables measured onboard by NMEA sensors.

Penerangan Jalan Umum Tenaga Surya: Studi Kasus di Kota Pangkalpinang

This research was conducted to design public street lighting photovoltaic, based on SNI 7391:2008 concerning specifications of public street lighting in urban areas with several parameters that were considered by poles, lights used, intensity of light needed, number of lights needed and supporting equipment for public street lighting photovoltaic. Currently, Jenderal Sudirman road in the city of Pangkalpinang along 1.5 km uses electricity from PLN with 30 units of 150 watt SON lamps and 11 lux light intensity. The design obtained for street lighting photovoltaic while still meet SNI for light intensity, obtained supporting equipment for solar street lighting, namely 31 unit of 8 meter octagonal poles with specifications of 40 watt LED lights for each cross arm, 1 unit of 100 Wp solar panels, unit of 100 Ah VRLA batteries and 1 unit of solar charger controller (10A, 12V / 24V).

Modeling the Charge and Discharge Behaviors of an AGM Lead-Acid Battery

An absorbent glass mat (AGM) lead-acid battery is a type of valve-regulated lead-acid (VRLA) battery. An AGM lead-acid battery differs from a flooded lead-acid battery in that the sulfuric acid is absorbed in a very fine fiberglass mat, making the battery spill-proof. The leading advantages of AGM type are a higher specific power, lower internal resistance, five times faster charge speed than the flooded version, and the ability to deep cycle. AGM lead-acid batteries are found in high-end vehicles equipped with more electronic devices and making inroads into the start-stop function of cars. A validated mathematical model for the accurate prediction of the charge and discharge behaviors of an AGM lead-acid battery in real-world driving conditions is necessary to ensure that the battery can provide enough power for the rising number of electrical components. In this work, a method of modeling the charge and discharge behaviors of an AGM lead-acid battery under various operating conditions is presented. This work adopts a simple modeling approach by considering Ohm’s law and charge conservation on the electrodes based on the simplified polarization characteristics of the electrodes. By not computing the potential distribution of electrolyte phase and the transport phenomena of ionic species, the modeling method in this work cuts down considerable computation time in comparison with rigorous electrochemical models. The model is validated by comparing the modeling results with the experimental measurements.

New 2.1 V Lithium- Ion Battery with Sulfurized Polyacrylonitrile (SPAN) Anode and LiMn2O4 Cathode

Sulfur/polyacrylonitrile (SPAN) composites are demonstrated as one of the interesting anode materials for lithium ion battery due to its high theoretical capacity, low cost and environmental friendliness. Herein, we investigated the electrochemical properties of SPAN composite as the anode material and LiMn2O4 (LMO) cathode for sulfur-lithium ion battery in carbonate based electrolyte for the first time. Sulfur as an anode coupled with a lithium-ion intercalation cathode creates a unique Li-ion/sulfur chemistry, realizing the highest energy density ever achieved, along with high safety and excellent cycle-life. The cell delivered a reversible discharge capacity of 1378.16 mAh/g at 0.1 C with specific capacity retention of 90.86% after 150 cycles. At 1 C, the capacity retention was 807.96 mAh/g after 400 cycles with an average decay rate of 0.7 mAh/cycle and average columbic efficiency of 99.5 % and its rate capability delivers a highly reversible capacity of 868.27 mAh/g at 2 C. The full SPAN/LMO cell is able to deliver a record high energy density of 185 Wh/kg (total electrode mass) and a power density of 270 W/kg (total electrode mass) at 1 C within the voltage ranging from 1 to 3.2 V. This new type of batteries surpasses current lead acid or VRLA batteries in gravimetric energy density four times. The capacity fading at 55 ℃ is mainly caused by the deposition of manganese on SPAN anode as XPS result confirmed. However, shuttling manganese was not observed when the cell was cycled at 25 o C. This strategy can be applied for other sulfur composite to provide a route for the development of high performance, cost effective and environmental benignity lithium ion based rechargeable batteries and the demonstrated cell with high rate and high capacity opens up new application opportunities for various electrical energy storage. Keyword: - non-aqueous sulfur battery; SPAN composite; high capacity; energy storage

Implementation of Solar Electricity and Water Filtration systems for a Smart House

The use of fossil fuels as a source of energy is one of the problems faced by the government nowadays. These cause harmful effects not only on humans, but also on the environment. Another problem is the supply and sanitation of water. The supply is becoming limited especially in rural areas and the sanitation is not being assured. In this research paper, the uses of solar energy and water as alternative sources are discussed. This research implemented solar electricity and water filtration systems for home use. Through these systems, the user can save a minimum of 20% of specific electricity wattage and save a certain amount of filtered water depending on the amount of rainwater collected. The materials used are Solar Panel, AGM Battery, Grid-tie Inverter, Charge Controller, Reverse Osmosis System, LCD, gizDuino+, ATMEGA 324P, and various components like resistors, transistors, and wires that made up the monitoring system’s circuit.

Comparative Study of Weekly Discharge Rate of Two Solar Batteries Commonly Used in Anambra State

The purpose of this study is to compare the weekly discharge rate of two solar batteries commonly used in Anambra State. The batteries considered were the Indian made battery with specification Luminous, Deep cycle sealed maintenance free batteries solar application, Lum 12V 100Ah 20hr and 3DGP161433 and Chinese made battery with specification Sun-Test std gel battery, 12V-100Ah, 010716w, Cycle use 14.4-15.0V, Stand by use; 13.5-13.8V and Initial current: less than 30A were used to power 2 stand-alone security lights at the Faculty of Physical Sciences, Nnamdi Azikiwe University, Awka. The technical assessment was based on measuring their output voltages bihourly from 19.00 hr to 7.00 hr and estimation of weekly discharge rate of these batteries for a period of two months (eight weeks). From the analysis, the Indian made solar battery has insignificant discharge tendency for the first eight weeks of its use having its discharge rate of -0.034, -0.038, -0.042, -0.037, -0.039, -0.038, -0.039 and -0.036 Volts/hr per week from week one to week eight respectively whereas the Chinese made solar battery has a relatively high discharge rate of Voltage/hr per week within the first eight weeks of its use having its rate at -0.095, -0.213, -0.103, -0.1, -0.104, -0.1, -0.083 and -0.109Volt/hr per week from week one to week eight. Also, while the Indian made battery is observed to be relatively stable, the Chinese made battery was observed to be very erratic and highly susceptible to discharge within the first eight weeks (two months) of its use. Hence, it is concluded that Indian made battery is preferred to that of Chinese made battery for optimal performance of stand-alone PV syste.

Study on synthesis and application of tetrabasic lead sulfate as the positive active material additive for lead-acid batteries.

Tetrabasic lead sulfate (4BS) was used as a positive active material additive for lead-acid batteries, which affirmatively affected the performance of the battery. Herein, tetrabasic lead sulfate was synthesized from scrap lead paste that was formed through the production process of the lead-acid batteries. This solves the disposing problem of the scrap lead paste that is challenging in the production of the lead-acid batteries. Scrap lead paste was first pre-treated and the 4BS with high purity and crystalline was synthesized by sintering at the temperature of 450°C and hold time of 7 h. As demonstrated by X-ray diffraction and scanning electron microscopy test and Material Studio software calculation, the purity of synthesized 4BS is higher than 98 wt%, small particles have pillar forms and are evenly distributed. Moreover, the synthesized 4BS of 1 wt% was added to the positive lead paste and then valve-regulated lead-acid battery was made after the pasting, curing and formation processes. The effectiveness of the lead-acid batteries after adding 4BS as crystal seeds was evaluated, and the 100% charge–discharge cycle life of the new battery (523 times) was about 1.4 times higher than that of general lead-acid batteries (365 times).