battery management system (BMS)

"The aim of the real time automotive battery monitoring system is to prevent the discharge of a car battery beyond the point of restarting the car. This is a common issue that can leave a person stranded and highly inconvenienced. Also, draining a battery drastically reduces the life of a car battery. The developed embedded system will control and monitor different parameters of the rechargeable battery. Such systems are essential for optimum utilization of the battery. This system will be useful for electrical car to understand health condition of the rechargeable battery. It will be easy to take decision of recharging the battery or replace the battery. This embedded system comprises real time microcontroller platform and electrical emulation of sensors and actuators for read, process, monitor, control and stores the acquired data for further analysis. BMS system monitors and controls very important battery parameters. The metric of development and test efficiency is typically consists of factors i.e. cost, duration, safety and feasibility. The BMS is a cheap, simple-to-install and easy-to-use. This BMS is useful in every battery powered systems and vehicle for fuel status. Cars run on lead-acid batteries and so disposal of them is very bad for the environment. It is also costly and time-consuming to get a battery replaced. Finally, running on a bad battery can reduce the life span of the car’s alternator. The BMS is also used for calculating secondary reports and reporting the generated data. The BMS also helps in controlling or balancing battery environment. Keywords: Automotive and Intelligent Instrumentation ; Battery Management System; Lead acid battery; Embedded Systems; State of Charge (SOC) "

Lithium ferro phosphate (LiFePO 4) has a promising battery technology with high charging/discharging behaviours make it suitable for electric vehicles (EVs) application. Battery state of charge (SOC) is a vital indicator in the battery management system (BMS) that monitors the charging and discharging operation of a battery pack. This paper proposes an electric circuit model for LiFePO 4 battery by using particle filter (PF) method to determine the SOC estimation of batteries precisely. The LiFePO 4 battery modelling is carried out using MATLAB software. Constant discharge test (CDT) is performed to measure the usable capacity of the battery and pulse discharge test (PDT) is used to determine the battery model parameters. Three parallel RC battery models have been chosen for this study to achieve high accuracy. The proposed PF implements recursive bayesian filter by Monte Carlo sampling which is robust for non-linear and/or non-Gaussian distributions. The accuracy of the developed electrical battery model is compared with experimental data for verification purpose. Then, the performance of the model is compared with experimental data and extended Kalman filter (EKF) method for validation purposed. A superior battery SOC estimator with higher accuracy compared to EKF method has been obtained.

Hybrid energy system provides alternative solution for better use in renewable energy system. The use of electric vehicle technology plays a crucial role in playing solution for environmental concern. This work provides fuzzy controller based hybrid energy management system of battery for electric vehicle. Some intelligent techniques are used for optimized the performance of system. First part of system describes the battery with supercapacitor with PV array and then second part describes the fuzzy based controlling system for monitoring the state of battery. The use of fuzzy provides the reduction of any other conventional method in system. All simulations are done with MATLAB/Simulink Model.

Cell imbalance can cause negative effects such as early stopping of the battery charging and discharging process which can reduce its capacity. In the previous active balancing research, the energy used for the balancing process was taken from the cell or battery pack, resulting in drop of electric vehicle driving range. In this paper, a cell charger based battery balancing system is proposed with a reduction in the number of switches. The use of a cell charger aims to increase the usable energy of the battery pack, since the energy used for the balancing process is taken directly from the grid. The use of fewer switches aims to reduce the cost and space used on the battery management system (BMS) hardware. The charger used for the balancing process has a maximum current of 3 A and a maximum voltage of 3.65 V while the number of switches used is n+5 for n batteries. A 15S1P 200 Ah LiFePO4 battery pack consists of 15 cells used for testing purpose. The test results show that the time needed to equalize the 15 cell battery voltage reaches 6 hours from the difference between the highest and lowest battery cell voltages of 145.1 mV to 15.1 mV.

Sorting of electronic components are major issues in the educational electronic laboratories and device manufacturing industry. The effective sorting and management of the electronic color coded components are useful in classification and reduction of electronic waste. Many a time there is possibility that usable electronics components are thrown along with damaged or failure components prone to increase e-waste. In order to deal with this issue, use of sorting mechanism plays a significant role. Every electrical system is getting digitalized and leads to reduce human intervention, efforts and errors. The digitized system will make sure of getting the best product and quality. The proposed research work deal with sorting of different colour coded passive components and among the resistor is selected as a case study. The sorting system of the components is developed with the help of MATLAB tool because it integrates computation, visualization and data processing. The different algorithms are available and used to detect color code of the object i.e. Gaussian blurring, k-means vector quantization and Laplace. Image analysis, exploration and visualization are done with scientific and engineering graphics. The developed simulator gives results in proper manner using graphics user interface.

The shrink in accessibility of petroleum products and increment in asset request are eventual outcomes for Electrical Vehicles (EVs). The battery has an impact on the performance of electrical vehicles, the driving range. Lithium ion (Li-ion) chemistry is extremely sensitive to overcharge and deep discharge, which can harm the battery, shortening its period of time, and even inflicting risky things. The Battery Management System (BMS) comprises of the consequent parts: management, equalization and protection. Of the three components, equalization is that the most crucial with respect to the durability of the battery framework. The ability of the full pack diminishes rapidly amid the procedure which leads to degradation of the full battery framework. This condition is extreme once the battery incorporates a more number of cells in series and frequent charging is conveyed through the battery string. The cell imbalance during charging, discharging is a major issue in battery systems used in EVs. To circumvent the cell imbalance, cell balancing is used. Cell balancing enhances battery safety and extends battery life. This paper discusses about different active balancing method to increase the life span of the battery module. Based on the comparison, the inductor based balancing method for 60V battery system is implemented in the MATLAB/Simscape environment and the results are discussed.

— Battery has an important role as energy storage in electricity system utilization such as in electric vehicle and in smart microgrid system. Battery Management System (BMS) is needed to treat the dynamics of energy storage process in the battery in order to improve the performance and extend the life time of battery. In this paper, BMS cell monitoring and protection has been designed and tested for Lithium Ferro Phosphate (LFP) battery cells. The BMS cell monitoring function has been able to measure the battery parameters such as the voltage and current dynamics of each cell. The data taken from the BMS cell monitoring experiment is used to estimate the state of charge (SOC) of battery which is based on coulomb counting with coulomb efficiency ratios. The BMS cell monitoring function has successfully demonstrated the presence of unbalanced cell voltages during both processes of charging and discharging as well. From the analysis, the existence of capacity and energy fades was also investigated for every discharging and charging cycles. Based on the BMS cell protection experiment results, overcharged and over discharged protections have successfully been demonstrated for the battery cells. The charging process is disabled when the voltage of the corresponding battery cell exceeds its high limit (HLIM) at 3.65V, and the battery will be available for charging when all of the cell voltages are below their boundary limits (CAVL) at 3.3V. The discharging process will be disabled when the battery cell voltage is lower than the corresponding low limit (LLIM) at 2.5 V. The battery will be available again when all battery cell voltages are above their discharge available (DAVL) voltage at 2.8V. The proposed BMS cell monitoring and protection has shown its function as a data acquisition system, safety protection, ability to determine and predict the state of charge of the battery, and ability to control the battery charging and discharging.

Towards a sustainable future, the adoption of eco-friendly distributed generation (DG) and electric vehicle (EV) in the distribution network is increasing rapidly. However, the stochastic nature of renewable-based DGs and high penetration of EV charging have some adverse impacts on power quality in regional distribution grids. To mitigate these problems, we have presented a novel technique of bidirectional power flow control for DG-coupled battery energy storage system (BESS). The verification and validation of the proposed algorithm have been done by performing several case studies considering real-time practical solar photovoltaic (PV) irradiation and wind speed data, and actual EV load data. For the case studies, we adopted the IEEE 13 node distribution feeder as the testbed which is implemented in the MATLAB/Simulink environment. We observed that, by intelligent charging and discharging of BESS, the proposed method controls fast-varying power generated from PV effectively, and i...

While decreasing their cost, lithium-ion batteries began to enter a vast domain for energy storage field, including solar systems and electric vehicles, due to their high energy density compared to other types. Besides, li-ion batteries require a safe and secure ground to reach the best performance and decrease the explosion risk. The safe operation of the battery is based on the main protection features and balancing the cells. This study offers a battery BMS design that protects li-ion batteries from overcharging, over-discharging and overheating. It is also offering passive cell balancing, an uninterrupted power source to load, and monitoring data. The used controller is Arduino mega 2560, which manages all the hardware and software protection features. Software features that include 1) variable charging speed according to the batteries charging status, 2) measuring the batteries state of health and state of charge, 3) controlling the uninterrupted driver, 4) regulating the charge and discharge voltage, and 5) measure and display all readings.

While decreasing their cost, lithium-ion batteries began to enter a vast domain for energy storage field, including solar systems and electric vehicles, due to their high energy density compared to other types. Besides, li-ion batteries require a safe and secure ground to reach the best performance and decrease the explosion risk. The safe operation of the battery is based on the main protection features and balancing the cells. This study offers a battery BMS design that protects li-ion batteries from overcharging, over-discharging and overheating. It is also offering passive cell balancing, an uninterrupted power source to load, and monitoring data. The used controller is Arduino mega 2560, which manages all the hardware and software protection features. Software features that include 1) variable charging speed according to the batteries charging status, 2) measuring the batteries state of health and state of charge, 3) controlling the uninterrupted driver, 4) regulating the charg...

Cell imbalance can cause negative effects such as early stopping of the battery charging and discharging process which can reduce its capacity. In the previous active balancing research, the energy used for the balancing process was taken from the cell or battery pack, resulting in drop of electric vehicle driving range. In this paper, a cell charger based battery balancing system is proposed with a reduction in the number of switches. The use of a cell charger aims to increase the usable energy of the battery pack, since the energy used for the balancing process is taken directly from the grid. The use of fewer switches aims to reduce the cost and space used on the battery management system (BMS) hardware. The charger used for the balancing process has a maximum current of 3 A and a maximum voltage of 3.65 V while the number of switches used is n+5 for n batteries. A 15S1P 200 Ah LiFePO4 battery pack consists of 15 cells used for testing purpose. The test results show that the time...

—Battery monitoring is vital for most electric vehicles (EVs), because the safety, operation, and even the life of the passenger depends on the battery system. This attribute is exactly the major function of the battery-management system (BMS)—to check and control the status of battery within their specified safe operating conditions. In this paper, a typical BMS block diagram has been proposed using various functional blocks. The state of charge (SOC) estimation has been implemented using Coulomb counting and open-circuit voltage methods, thereby eliminating the limitation of the stand-alone Coulomb counting method. By modeling the battery with SOC as one of the state variables, SOC can be estimated, which is further corrected by the Kalman filtering method. The battery parameters from experimental results are integrated in the model, and simulation results are validated by experiment.

The high level of energy and power density of Lithium-ion and Zinc batteries amongst electrochemical batteries such Lead acid battery etc. makes them suitable as the energy storage in electric, hybrid electric vehicle, and plug-in vehicles (EV/HEV/PHEV). The battery management system is an electronic system that manages battery. One of the requirements in electrical system is rechargeable battery and its precise management. The Battery management system (BMS) monitors very important battery parameters i.e. state of charge, state of health, coolant flow for air or fluid, ampere hour counting, terminal voltage and flowing current (in and out).Open circuit voltage and integral of discharging current of the battery be used for estimation of SOC and are the function of SOC. The on line measurement and comparison of the predicted and measured terminal voltage and integral of current provides a tool for estimating the SOC and SOH. The BMS is also used for calculating secondary reports and ...

Due to substantial generation and demand fluctuations in standalone green microgrids, energy management strategies are becoming essential for the power sharing purpose and regulating the microgrid voltage. The classical energy management strategies employ the maximum power point tracking (MPPT) algorithms and rely on batteries in case of possible excess or deficit of energy. However, in order to realize constant current-constant voltage (IU) charging regime and increase the life span of the batteries, energy management strategies require being more flexible, equipped with the power curtailment feature. In this paper, we propose a coordinated and multivariable energy management strategy to control the operation of a wind turbine and a photovoltaic array of a standalone DC microgrid, by controlling the pitch angle and the switching duty cycles, to ensure that they act as controllable generators. The proposed strategy is developed as a nonlinear model predictive control (NMPC) algorithm. It is shown that applying the proposed controller to a sample standalone dc microgrid, the battery bank is charged according to the IU charging regime. The variable load demands are also shared accurately between generators in proportion to their ratings. Moreover, the DC bus voltage is regulated within a predefined range, as a design parameter.

The Battery management System (BMS) refers to the process of maintaining the battery and its temperature conditions optimum for maximum performance of them. BMS system for huge industries has been managed to give backup supply the critical loads and to save Diesel Generator running time and cost. The main components which are to be taken care are charging current, discharging current, weight, temperature with respect to time. Implementation of fullScale measurement, calculation, prediction and representation with easy perspective User interface and also reducing the usage of Diesel Generator by making the battery system available always to supply back up power. Furthermore, stimulating an alarm responding to the battery leakage and reducing the risk of accumulation of hazardous and inflammable H2 gas. Finally, the product includes remote calculation and display, in a pictograph on an Android Application.

The amount energy stored and used from batteries has quadrupled over the last decade. This calls for an effective battery monitoring system, that can predict the life of a battery with respect to the load connected, and accounts for battery degradation over time.
Therefore we intend to create a real time battery monitoring system that will be able to provide the user with the constant state of charge of their battery, time till empty if run on current load and the degradation occurring to the battery over time as a function of its internal resistance and change in time taken for charging to the same value.
The system we describe below, works on the principle of impedance racking, which is a more advance take on traditional coulomb counting method for battery state of charge estimation. The system uses open circuit voltage(OCV) readings and coulomb counting to predict that state of charge of a battery, its battery life and degradation factors. Lastly, the data are displayed through the serial communication port of the Microcontroller used, which can be extended to small LCD screens or a web interface. We hope our system will enable the user to utilize the energy stored effectively, replace batteries timely, and reduce cost of replacement effectively.

Electric mobility contributing to greater extent to balance the energy and power demands, energy storage units as well as environment safety for current automobile sector. Electric vehicle has major efficient features of zero combustion, longer charging and discharging cycle which plays a vital role to replace the ongoing increase in price of petroleum fuels and its harmful effect son environment with their degrading store. Many non-conventional energy sources like solar, tidal, wind etc. Can be used to generate energy and store it in suitable types of batteries to run these vehicles. The Different types of batteries like lead acid, lithium ion, nickel bromide are used as an energy storage devices for these electric vehicles. But with many advantages these batteries has some structural and thermal issues if not designed or connected properly. These issues are capacity loss, cell balancing, thermal runaway, reduction in battery life etc. therefore much focus need to give on proper battery connections considering its working parameters. Possible types of connections for batteries are active, passive and semi active as per their connections in series and parallel type. These connections depends on increasing the voltage and capacity of the battery. For series combinations apposite terminals of batteries are connected to each other, in which current remains constant and battery voltage is summed up to increase for maintaining the same capacity or ampere hour (Ah) rating of batteries. Whereas in parallel connections same terminals of the batteries are connected to each other in which voltage remained constant and battery current is summed up to rise. This is needed when we need to double the battery capacity or ampere hours (Ah) rating according to your system needs while maintain the same level of voltages. Each connections has its significance for battery performance. The present work focused on various design parameters of electric vehicle i.e. Comparative analysis of both series and parallel connection of batteries through its circuit connection, active and passive cell balancing of battery cells. This analysis will be carried out in Experimental with simulation study using by analysing the behaviour of it on battery performance characteristics such as state of charge, voltage and current variation as per load cycle.

Functional electrically conductive fabric with acceptable mechanical properties, which could be applied in electromagnetic shielding, was developed. Conductive cotton fabrics (cotton/PANI, cotton/Mn, cotton/Cu, and cotton/Co) were prepared by in situ chemical oxidative polymerization for (cotton/PANI) and pad dry curing method was used for nanometals application. The Nano size of the metals and polyaniline inclusion were proven through both Dynamic Liquid Scattering (DLS) and X-ray diffraction (XRD) which showed an increase in crystallite density in unit space and the nano-particles ranged from 100-200 nm. The effect of gamma irradiation on different treated cotton fabrics was investigated. The mechanical properties against irradiation dose showed an improvement up to 40 kGy, for all treated fabrics. On the other hand, Young's modulus for untreated cotton recorded the lowest value, while cotton/Co recorded the highest one. Moreover, both AC (Alternating Current) and DC (Direct current) conductivities values can be calculated. In DC conductivity cotton/PANI was found to be more conducive than the remainder of the treated fabric by surface met-allization with transition metals; while in AC conductivity cotton/Mn was found to be more conducive than the rest of the treated samples. The conductivity value increases by increasing the gamma irradiation dose for cotton/PANI fabric. Also, g-factor values can be estimated from ESR signals and vary from 0.009 up to 0.059 for conductive

High coulombic efficiency (CE) usually indicates a long battery cycle life. However, the relationship between long-term CE evolution and battery degradation is not fully understood yet. This paper explores the behavior of long-term CE and clarifies its relationship with capacity degradation. Cycle life tests are conducted on two types of mainstream commercial lithium-ion batteries. An incremental capacity (IC) analysis is then employed to identify battery aging mechanisms. Experimental observations along with in-depth discussions are presented regarding battery degradation, aging mechanisms, and CE evolution. From the experimental results, two typical degradation patterns are recognized. From the IC analysis, we observed that, in addition to a loss of lithium inventory, a loss of active material accelerates battery degradation and brings down CE values. From an electrochemical perspective, this paper establishes the relationship between CE evolution and capacity degradation. This relationship can help develop battery degradation models, estimate battery health states, and provide early failure warnings for a battery management system.

The Formula SAE Electric competition is a collegiate autocross event in which teams design, build, and race an open-wheeled electric race car. The main motivation is the efficiency advantage of electric motors over internal combustion motors. This thesis presents the design and evaluation of two generations of Portland State University electric race cars.

Buck and Boost modes, which working alternately. Hence, it has two output directions: Buck mode for decreasing the voltage and Boost mode for increasing the voltage at certain levels. In this work, we applied a non-isolated topology of the Bidirectional DC/DC converter for electric vehicle, that is mini all-terrain vehicle (ATV). We set a Buck mode to charge the Supercapacitor when the battery current and the Supercapacitor voltage are lower than considered level. Whereas the Boost mode was used to discharge as well as buffer the mini ATV when the battery current and the Supercapacitor voltage are higher than considered level. The discussion of Buck mode has been presented in previous work, so in this work, we focus on the Boost mode analysis only. This mode is set to increase the Supercapacitor's voltage. The Supercapacitor with 25 VDC/8 Farad was used as the secondary main power inside the 22.2 VDC / 5000 mAh LiPo battery of the mini ATV motor. The mini ATV requires 36 VDC to work. Thus, it must be boosted first from 22.2 to 36 VDC using an external Boost converter. Moreover, it must be maintained at 36 VDC. Based on the requirement, we first design the bidirectional DC/DC converter involving the mathematical calculation and then simulate it into LTSpice®. The Printed-Circuit Board is then lay-outed and mounted. Later, we connected the designed system to mini ATV motor and tested the performance as well. According to the laboratory test, the Bidirectional DC/DC converter can increase (Boost) the voltage of the Supercapacitor from a certain level to 36 VDC. On the other hand, it can maintain 36 VDC. The central control in this system uses the STM32F4 Microcontroller, while the battery monitoring system employs the STMStudio.

—Voltage interruption can be happened by several reasons like blackout, brownout, noise, spike etc. Those incidents have consequential effect on computer's hardware such as data losses, burning of sensitive equipment etc. So, UPS broadly called an uninterruptible power supply device is used in computer to provide a backup power source which will maintain the consistency in voltage and flow of electricity which in turn will provide consistent power input. Batteries are used as energy storage device in UPS which store electric energy during charging state and discharge that electric energy during any kind of interruption to provide backup as additional power source for the computer. So, the most important integral part of UPS is the battery pack which is used as energy storage device in UPS. Main goal of this paper is to design the suitable battery pack for UPS so that it can give maximum backup range to the computer within a certain economical range or cost limit. Also, another goal is to analyze the electrical and thermal parameters of the designed battery pack and cell and suggest better solutions to make the wet battery cell maintenance free (no need of addition of water). Index Terms—uninterruptable power supply, energy storage device, lead acid battery, battery maintenance, wet cell battery.

Until recently, the relatively high levelized cost of electricity from solar photovoltaic (PV) technology limited deployment; however, recent cost reductions, combined with various financial incentives and innovative financing techniques, have made PV fully competitive with conventional sources in many American regions. In addition, the costs of electrical storage have also declined enough to make PV + battery systems potentially economically viable for a mass-scale off-grid low-emission transition. However, many regions in the U.S. (e.g. Northern areas) cannot have off-grid PV systems without prohibitively large battery systems. Small-scale combined heat and power (CHP) systems provide a potential solution for off-grid power backup of residential-scale PV + battery arrays, while also minimizing emissions from conventional sources. Thus, an opportunity is now available to maximize the use of solar energy and gain the improved efficiencies possible with CHPs to deploy PV + battery + CHP systems throughout the U.S. The aim of this study is to determine the technical viability of such systems by simulating PV + battery + CHP hybrid systems deployed in three representative regions in the U.S., using the Hybrid Optimization Model for Electric Renewable (HOMER) Pro Microgrid Analysis tool. The results show that the electricity generated by each component of the hybrid system can be coupled to fulfill the residential load demand. A sensitivity analysis of these hybrid off grid systems is carried out as a function capacity factor of both the PV and CHP units. The results show that conservatively sized systems are technically viable in any continental American climate and the details are discussed to provide guidance for both design and deployment of PV + battery + CHP hybrid systems to reduce consumer costs, while reducing energy- and electricity-related emissions.

In this paper, a standalone Hybrid power generation
system with improved power quality is proposed. The proposed
system consisting of Wind energy conversion system (WECS),
Diesel generator system, PV generation system and Battery
energy storage system (BESS).A hybrid system consists of wind,
solar PV, diesel generator, battery, and a controller. Tip Speed
Ratio (TSR) control with Field Oriented Control (FOC), method
was used for implementing Maximum Power Point Tracking
(MPPT) for wind system, variable step Perturb & Observing
(P&O) method for solar and optimum fuel consumption
technique for Diesel engine. MATLAB/Simulink was used to
build the model and simulate the system. The result shows the
better performance of the system under the variation of input
constraints as well as output constraints.

This paper deals with the management of Energy Storage System (ESS) connected in a microgrid with a PV array and regulate the battery charge, hold and discharge operations using DC-DC bidirectional converter based on the requirement of the Load. The PV array along with the battery and load is simulated for various conditions such as PV supplying and charging the battery, PV supplying only the load, battery supplying the load and PV-Battery both supplying the load. The output parameters like voltage, current and power graphs are plotted and analysed for each condition. The entire paper is simulated on Matlab-Simulink environment.

This paper presents a novel intelligent energy management system (IEMS) for a DC microgrid connected to the public utility (PU), photovoltaic (PV) and multi-battery bank (BB). The control objectives of the proposed IEMS system are: (i) to ensure the load sharing (according to the source capacity) among sources, (ii) to reduce the power loss (high efficient) in the system, and (iii) to enhance the system reliability and power quality. The proposed IEMS is novel because it follows the ideal characteristics of the battery (with some assumptions) for the power sharing and the selection of the closest source to minimize the power losses. The IEMS allows continuous and accurate monitoring with intelligent control of distribution system operations such as battery bank energy storage (BBES) system, PV system and customer utilization of electric power. The proposed IEMS gives the better operational performance for operating conditions in terms of load sharing, loss minimization, and reliability enhancement of the DC microgrid.

A lumped Electro-thermal model of a large format high power Li-Ion cell is introduced in this paper. The model is able to meet the real time implementation requirements; hence it finds its application in Battery Management System (BMS) of an Electric Vehicle (EV). The model is evaluated in Hardware in the Loop (HIL) setup to verify online estimation of cell surface and internal temperature estimation for an on-board EV application. In this study, the cell is considered as a single homogeneous layer and the heat is generated in the centre point of the cell and flows in one direction towards the surface. For this modelling purpose, reversible and irreversible heat in the cell is considered. Irreversible heat consists of the Joule heating effect due to internal resistance of the cell. For instance these values are then calculated with sufficient electrical cell model and evaluated both offline and in real time calculation. Reversible heat is a result of entropy effect which can be negative or a positive value depending on the direction of current flow during charging and discharging process of the cell. Other heat transfer mechanism such as conductive heat transfer and convective heat transfer are also included into the model. This paper introduces a reference case test used to calculate the required necessary coefficients both for parameterization of electrical model and thermal model. The battery setup in the laboratory for measuring the cell surface temperature as reference data as well as cell sandwich setup for evaluating the internal temperature of the cells is explained in detail. Fundamental equations to develop the thermal model are introduced and the model is evaluated in both offline and real time mode.

Battery-powered Electric Vehicles (BEVs) such as electric cars, use the battery as the main power source to
drive the motor, in addition to lighting, horn, and other functions. Currently, Balai Besar Bahan dan Barang Teknik
(B4T) has been conducting research in Lithium-ion (Li-ion) battery prototype for an electric vehicle. However, the
management system in accordance with the electrical characteristics of the battery prototype is still not available.
Thus, to integrate the battery prototype with electrical components of the electric vehicle, it is necessary to design
Battery Management System (BMS). Two important battery parameters observed are State of Charge (SOC) and
State of Health (SOH). The method used for SOC was Coulomb Counting. SOH was determined using a
combination between Support Vector Machine (SVM) and Relevance Vector Machine (RVM). Based on the
experiments by using BMS, the battery performance could be more controlled and produces a linear curve of SOC
and SOH.

— In this research work, we demonstrate state-of-charge (SoC) estimation using support vector regression (SVR) approach for a high capacity Lithium Ferro Phosphate (LiFePO 4) battery module. The proposed SoC estimator in this work is extracted from open circuit voltage (OCV)-SoC lookup table which is obtained from the battery module discharging and charging testing cycles, using voltage and current as independent variables. The SoC estimation based on SVR gives a perfectly linear curve fitting with its reference within the range of 37.5% to 90% while the rest hysteresis due to the discharging and charging process is compensated using OCV-SoC curve as the training data set. The SVR estimates the battery module SoC with RMSE of 2.3% over the whole test and the maximum positive and negative error is 4%, which means that it shows good accuracy. Keywords— State of Charge, Support Vector Regression, Coulomb Counting, Open Circuit Voltage, Lithium Ferro Phosphate Battery Module.

This paper proposes a new design and
implementation of an isolated bidirectional dc-dc
converter to interface between a high voltage DC
bus (HVDC) and a low voltage DC battery
(LVDC). It features zero voltage switching
regardless of the direction of the power flow,
resulting in lower switching losses and an efficient
converter. The details operation principles, as well
as the design considerations, are presented. The
simulation and experimental results have
validated the characteristics of the converter. A
prototype, which interfaces a 400V dc bus and
48V battery bank with a power rating of 2.5kW,
was developed to verify the validity and
applicability of this proposed converter.

Pentingnya penggunaan teknologi yang rendah emisi karbon menyebabkan penggunaan baterai semakin luas, antara lain untuk backup daya, penyeimbang fluktuasi daya dari pembangkit listrik energi baru terbarukan, dan kendaraan listrik. Pada penggunaan sistem penyimpanan energi, informasi State of Charge (SoC) sangat dibutuhkan supaya tidak terjadi pemendekan umur baterai yang diakibatkan oleh ketidakseimbangan muatannya. Pada penelitian ini dibuat prototipe Battery Management System (BMS) untuk empat baterai lead acid berkapasitas 100 Ah, yang memiliki fungsi menyeimbangkan muatan melalui pengamatan SoC menggunakan metode coulomb counting. Karena kesetimbangan muatan setiap baterai dijaga agar tetap optimal, maka sebagai hasilnya adalah durasi pengosongan baterai dapat ditingkatkan lebih lama. Kata kunci: state of charge, battery management system, lead acid, coulomb counting.

Since the advent of mobile telecommunication services into Nigeria in 2001, profound increase in the consumer's electronic market for mobile phones has been continually witnessed. However, this remarkable progress has resulted in the generation of large quantities of e-waste. This paper studies mobile phone usage behaviours and battery disposal among Nigerians. Certain hypotheses are formulated highlighting variables like sex, age, occupation, level of education, responsibility to the environment, knowledge of the respondents towards proper waste disposal and their relationships with mobile phone usage behaviour, and the intention for proper mobile battery disposal are tested. Results show that mobile phone users with higher levels of education have better mobile phone usage behaviours than those with lower levels of education. Also, majority dispose their phone battery indiscriminately which is an indication that there is no proper regulation on battery disposal. Moreover, relationship exists between occupation and the intention for proper battery disposal with corporate workers having the highest percentage of respondents willing to recycle used batteries without compensation for the act. Based on the outcome of the study, the need for consumer awareness, domestication of international conventions or enactment of local legislation to deal with the e-wastes, and the provision of infrastructure for the collection and processing of the wastes generated are recommended.

— In this paper, we discuss the design, simulation, and implementation of the bidirectional DC to DC converter circuit for charging a Supercapacitor. Fundamentally, the bidirectional DC-DC converter consists of buck and boost which working alternately each other. In this work, we implemented our design for electric mini ATV motor application. The Buck-mode is used for charging the Supercapacitor, while the Boost-mode is used for ATV motor's buffering (discharging). The electric ATV motor needs 36 VDC of the power supply. The Li-Po battery 22.2 VDC/5000 mAh is used as the main power on ATV motor, then stepped-up by external DC-DC boost converter module till 36 VDC. To charge the Supercapacitor (25 VDC/ 8 Farad), the 36 VDC should be stepped-down at least above 15 VDC to keep the circuit in a good performance and under 21 VDC to preserve the Supercapacitor health. Thus, we set the 18 VDC as an ideal voltage to charge the Supercapacitor. This paper focuses on the analysis of buck-mode (charging mechanism) only.