Browse Topic: Nickel-metal hydride batteries

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Battery TerminologyJ1715/2_202108 (Current)8/9/2021
This document contains definitions currently used in the automotive industry as they relate to energy storage and batteries for starting, lighting, and ignition applications, as well as for hybrid electric vehicles (HEV) and electric vehicles (EVs). It is intended that this document be a resource for those writing other battery, HEV, and EV documents, specifications, standards, or recommended practices. The use of the term “battery” in this document can be assumed to be a rechargeable battery (secondary battery). The terminology may be applied to other industries if desired.
Battery Terminology Committee
Recommended Practice for Performance Rating of Lead Acid and Nickel Metal Hydride Electric Vehicle Battery ModulesJ1798/1_202008 (Current)8/3/2020
This SAE Recommended Practice provides for common test and verification methods to determine lead acid and nickel metal hydride electric vehicle battery module performance. The document creates the necessary performance tests to determine (a) what the basic performance of EV battery modules is, and (b) if battery modules meet minimum performance specification established by vehicle manufacturers or other purchasers. Specific values for these minimum performance specifications are not a part of this document.
Battery Standards Testing Committee
Portable Emergency Lighting Systems for Flight Crew MembersARP1798B (Historical)7/14/2020
The purpose of this SAE Aerospace Recommended Practice (ARP) is to recommend general design and performance characteristics for hand-held portable, emergency lighting systems (note: the portable portion of this system that contains the lamp and reflector will be identified throughout the remainder of this document simply as a “flashlight”) intended for use by crew members of commercial aircraft during any emergency situation, within or outside of the aircraft cabin, where emergency lighting is required.
A-20C Interior Lighting - Test
Balancing Strategy for a Battery Applied in HEV Based on Bi-directional Flyback Converter and Outlier Detection2019-36-02421/13/2020
Dissipative cell balancing generates heat during its operation. Current techniques do not guarantee optimal balance of battery pack energy, requiring a high-cost Battery Management System (BMS) solution and wasting energy in the form of heat. Mild Hybrid Electric Vehicles uses the combustion engine to recharge the battery. Therefore, this feature requires a BMS balancing system capable of optimizing battery capacity and still be energy efficient. In this way, a non-dissipative balancing system would be interesting, especially if an algorithm works with the former non-dissipative balancing method, which efficiently determines which cells are unbalanced. In this paper, a methodology is proposed to perform non-dissipative balance of lithium-ion cells. This method considers which cells inside a certain range are considered balanced and cells outside this range are considered unbalanced. The range is given by the median of the cells terminal voltage summed with a threshold defined by experimental tests. Due the non-dissipative method presented herein is conceived through Flyback topology, the cells above this range are discharged and their extra energy is employed to charge the lowest charged cells, which were below the range. Simulation results which after the first 5 hours of balancing, the maximum difference does not exceed 1% and the standard deviation 0.5% until the end of the simulation, reducing SOC standard deviation by more than 33 times in one day operation. This result shows the strategy is promising to make a more efficient balancing mechanism for Mild Hybrid Electric Vehicles.
Marques, Felipe L. R., Aranha, Juliana C. M. S., Padela, Fernando F., Rosolem, Maria de Fátima N. C., Beck, Raul F.
A Novel Approach on Range Prediction of a Hydrogen Fuel Cell Electric Truck2019-28-251411/21/2019
Today’s growing commercial vehicle population creates a demand for fossil fuel surplus requirement and develops highly polluted urban cities in the world. Hence addressing both factors is very much essential. Battery electric vehicles are with limited vehicle range and higher charging time. So it is not suitable for the long-haul application. In further the hydrogen fuel cell-based electric vehicles are the future of the commercial electric vehicle to achieve long-range, zero-emission and alternate for reducing fossil fuels requirement. The hydrogen fuel cell electric vehicle range, it means the total distance covered by the vehicle in a single filling of hydrogen into the onboard cylinders. And here the prediction of the vehicle range is essential based on optimal parameters; vehicle acceleration, speed, trip time etc. before the start of the trip. If the driver starts the vehicle without range prediction and optimum driving strategy, will be led into midway vehicle stoppage and excessive energy consumption of the trip. This paper deals with different methods of electric vehicle range prediction and optimization, benefits and demerits are listed and discussed, to provide a fair idea on hydrogen fuel cell electric vehicle range prediction. Also, the paper has concluded with the optimization strategy for the vehicle range by analyzing the vehicle powertrain module, battery module, fuel cell module, hydrogen fuel supply module and the vehicle module. The strategy presented in this paper is aiming for assisting the driver in formulating a driving strategy and for trip planning based on optimization trip parameters, considering optimum energy consumption. One fuel cell vehicle tested with proposed strategies and results observed are matching. And there may be a scope of improvement if the researchers test on multiple vehicles.
Chandrasekar, C Venkatesh, Amruth Kumar, L R
Thermal Behavior Analysis of Lithium Ion Cells used in EVs and HEVs2019-28-016310/11/2019
The batteries for electric vehicles (EV) generate heat during discharging cycles. During these rapid discharge cycles the temperature of cell may increase above allowable limits. The high temperature of lithium ion cell is the primary factor affecting the cell performance and life. To develop efficient cooling mechanism for batteries, thermal behavior of secondary cell is must know. In this research, experimentally the thermal behavior analysis of cylindrical lithium ion cells at constant current discharge cycles with different current rates for each cycle is evaluated. The experiments were carried out at three discharge cycles of 1C, 2C and 3C rates and two battery chemistries namely NiMnCo and NiCoAlare considered for analysis. The instantaneous temperature of cell was measured using thermal imager and increase in overall cell surface temperature at different discharge rates, for entire discharging interval has been studied. An empirical relation for average surface temperature of cell at different current rates and depth of discharge has been obtained which may find application in defining the discharge algorithms. The rates of internal heat generation in both types of cell chemistry are calculated from the temperature data obtainedexperimentally. The extensive comparison of two cell chemistries on the basis of internal heat generation rate and rise in average surface temperature of cells for different current rates will help in battery selection and efficient designing of cooling mechanisms in battery pack. The experimental results in this research conclude that NiMnCo cell has least instantaneous internal heat generation rate at all current rates and is therefore safer and more thermally stable than NiCoAl cell.
Lonkar, Shubham Gaurishankar, Jain, Aatmesh, Bhalerao, Vikrant
WHAT WE'RE DRIVING19AUTP10_0710/1/2019
What first impresses about the GT is how easy it is to drive. Ingress is a little tricky over the wide sill, but once situated in the comfy driver's seat you use a strap to position the foot controls to your liking in a very cramped pedal box, and you have a few degrees of seatback angle to play with. The 3.5-L EcoBoost twin-turbo-charged V6 erupts to life from what feels like just behind your right earlobe, but settles quickly in a buzzing idle. Like many competition-focused machines, the V6 has a lightened-crank eagerness about it, but the “automatic” gearbox prevents any uneasiness about getting underway. Thanks to the rear-wheel-drive GT's low and centered mass, the engine can mutter away at low rpm while easily bringing the GT up to traffic speeds.
Q&A19AUTP09_159/1/2019
Few battery experts in the mobility industry can match the engineer/entrepreneur spirit of Subash Dhar. In a career spanning nearly 40 years, Dhar is co-inventor of over 45 patents and patent applications in the field of advanced batteries and fuel cell technologies. He led the team that developed and commercialized the nickel-metal hydride technology used in the Toyota Prius and has served in leadership positions at XALT Energy, Ener-1, EnerDel, and Ovonic. Dhar, a chemical engineer, recently founded a new company, American Battery Solutions, Inc., focused on module and pack engineering, assembly, and battery-systems integration. He's aiming for EV customers in the transportation, industrial-, and commercial-vehicle sectors who are seeking expertise at low and medium volumes. With $50 million in capital backing from NY-based KCK Group, Dhar purchased foundational assets from Bosch's North American battery-systems business, including a testing lab, a 172,000 square-foot plant in Ohio, and the lease on a 40,000 square-foot plant complex in Lake Orion, Michigan.
Toyota's proven fuel-cell stack reduces cost, complexity in H2 semi-truck19TOFHP06_146/1/2019
Hydrogen proponents likely know that Mirai means “future” in Japanese, but Toyota is only just beginning to explore how important the fuel cell stack in its H2-powered passenger car will be to the future of the company. Toyota debuted the third iteration of its hydrogen-powered, Class 8 semi-truck on Earth Day at the Port of Los Angeles as part of the Zero and Near-Zero Emissions Freight Facilities Project (ZANZEFF) run by the California Air Resources Board (CARB). Using a Kenworth T680 Class 8 model as a starting point, this truck was developed in partnership with Kenworth and replaces the original diesel engines that displaced either 12.9 L or 10.8 L, with two solid polymer electrolyte fuel-cell stacks that are exactly like the one used in each Mirai.
Blanco, Sebastian
Validation of Test Procedure for Measuring the Fuel Consumption of Production-Model FCVs2019-01-03824/2/2019
Factors affecting the measurement of the fuel consumption of FCVs were analyzed to reveal their sensitivity. The method for measuring fuel consumption described in WLTP is to measure the hydrogen consumption by using an electric precision balance and off-vehicle tanks (not on-vehicle tanks). This is unique compared with conventional vehicles such as petrol-engine vehicles and pure-electric vehicles. Therefore, we examined the sensitivities of the effect of hydrogen consumption determination, the effect of hydrogen supply pipe design, and the effect of hydrogen supply pipe management. The experiments were conducted with two production models of FCVs having different FC management systems. The effects were quantitatively evaluated by comparing the fuel consumption rate driving in WLTC.
Koshika, Kenichiroh, Niikuni, Tetsuya, Kawai, Terunao
WHAT WE'RE DRIVING19AUTP01_091/1/2019
Select “Sport+”, floor the gas pedal, listen to the engine and exhaust notes, and the essence of Mercedes-AMG's latest E 53 sedan is sensationally clear. But shouldn't this combo be V8 sourced from AMG's impressive repertoire rather than a 3.0-L in-line modular six, aided by an electrically-driven auxiliary compressor? “There are different reasons why we decided to use the six-cylinder inline for the E 53, but particularly because it is very compact,” said Christian Enderle, Director of Drive System Development, Mercedes-AMG. “Also, the six-cylinder inline runs more smoothly, as the primary and secondary inertia forces and torque are balanced.”
An Adaptive Neuro-Fuzzy Inference System (ANFIS) Based Model for the Temperature Prediction of Lithium-Ion Power Batteries07-12-01-00018/14/2018
Li-ion batteries have been widely applied in the areas of personal electronic devices, stationary energy storage system and electric vehicles due to their high energy/power density, low self-discharge rate and long cycle life etc. For the better designs of both the battery cells and their thermal management systems, various numerical approaches have been proposed to investigate the thermal performance of power batteries. Without the requirement of detailed physical and thermal parameters of batteries, this article proposed a data-driven model using the adaptive neuro-fuzzy inference system (ANFIS) to predict the battery temperature with the inputs of ambient temperature, current and state of charge. Thermal response of a Li-ion battery module was experimentally evaluated under various conditions (i.e. ambient temperature of 0, 5, 10, 15 and 20 °C, and current rate of C/2, 1C and 2C) to acquire the necessary data sets for model development and validation. A Sugeno-type ANFIS model was tuned using the obtained data. The numbers of input membership functions (MFs) representing the three input parameters of this model are 1, 2, 3, respectively. The input and output MFs are Gaussian curve and linear types, respectively. The optimization method is a hybrid one which is a combination of the back-propagation and the least squares methods. Compared with the validating data, the ANFIS model was able to accurately predict the battery temperature under various operating conditions. With fewer sensors for data acquisition and less computation complexity, this method could be a possible tool for the online temperature prediction of power batteries in electric vehicle applications.
Fan, Bin, Lin, Chunjing, Wang, Fang, Liu, Shiqiang, Liu, Lei
Industry Review of xEV Battery Size StandardsJ3124_201806 (Current)6/12/2018
This Technical Information Report (TIR) will review the global industry battery size standards for xEV vehicles to provide guidance on available cell sizes for engineers developing battery powered vehicles. The TIR will include a review of the sizes and standards that are currently being developed or used for cylindrical cells, pouch (or polymer) cells, and for prismatic can cells. The lithium-ion cell will be the focus of this survey, but module and pack level size standards, where available, will also be included.
Battery Cell Size Standardization Committee
Vehicle Electrification in Chile: A Life Cycle Assessment and Techno-Economic Analysis Using Data Generated by Autonomie Vehicle Modeling Software2018-01-06604/3/2018
The environmental implications of converting vehicles powered by Internal Combustion Engines (ICE) to battery powered and hybrid battery/ICE powered are evaluated for the case of Chile, one of the worldwide leaders in the production of lithium (Li) required for manufacturing of Li-ion batteries. The economic and environmental metrics were evaluated by techno-economic analysis (TEA) and Life Cycle Assessment (LCA) tools - SuperPro Designer and Gabi®/GREET® models. The system boundary includes both the renewable and nonrenewable energy sources available in Chile and well-to-pump energy consumptions and GHG emissions due to Li mining and Li-ion battery manufacturing. All the major input data required for TEA and LCA were generated using Autonomie vehicle modeling software. This study compares economic and environmental indicators of three vehicle models for the case of Chile including compact, mid-size, and a light duty truck. Autonomie was utilized to predict the fuel economy for the hybrid electric vehicle (HEV) and electric vehicle (EV) for each of the three vehicle types. The baseline fuel economy without vehicle electrification for each case was 44, 29, and 19 mpg, respectively. The LCA and TEA results suggest that vehicle electrification for the case of Chile would improve the metrics of sustainability and economic impacts at the nationwide level. The electrification of compact, mid-size, and a light duty truck, reduce the nationwide GHG emissions by 27%, 47%, and 37%, respectively, for the HEV scenario. Use of renewable energies in vehicle electrification, including hydroelectric and photovoltaic energies, currently 39% of the generation mix, and gasoline usage reduction reduces GHG emissions of the country. The EV scenario; however, increases the GHG emissions of the subcompact vehicle by 22%, whereas this scenario reduces the emissions of the mid-size and the light-duty truck by 25% and 47%, respectively. Use of crude oil, natural gas, and coal in Chile, currently 61% of the generation mix, contributes to increase the life cycle emissions for the EV scenario. The results of this research demonstrate that vehicle electrification has a significant impact not only in the reduction of GHG emissions but also in the economy of the country. Overall, this research will help policymakers and scientific communities to develop strategies to promote and research HEV and EV.
Quiroz-Arita, Carlos, Asher, Zachary, Baral, Nawa, Bradley, Thomas
A Technical, Environmental and Financial Analysis of Hybrid Buses Used for Public Transport2018-01-04244/3/2018
This paper presents a technical, financial and environmental analysis of four different hybrid buses operated under Buenos Aires driving conditions. A conventional diesel bus is used as reference and three electric hybrids equipped with different energy storage technologies, Li-Ion, NiMH batteries and double layer capacitors (ultracapacitors), are evaluated, along with a hydraulic hybrid platform which uses high-pressure accumulators as its energy buffer. The operating conditions of the buses are set using real driving GPS data collected from various bus routes within the city. The different vehicle platforms are modeled on AUTONOMIE SA and validated by comparing the obtained fuel consumption results to those reported by local transport authorities and values found in the literature. The embedded energy and CO2 emissions of each platform are estimated using GREET and the total cost of ownership of each vehicle is calculated and compared to that of the conventional bus. Furthermore, aging models are proposed to evaluate the life duration of the batteries and ultracapacitors. Results show that, independent of the energy storage technology, the fuel economy performance of all hybrids is highly dependent on the size and configuration of the powertrain and energy storage components. When optimized, all hybrids achieve significant fuel consumption reductions compared to a conventional diesel bus, however, the ultracapacitor based system seems to outperform the other technologies. The battery based electric buses achieve similar fuel consumption reductions, but the NiMH based batteries shows a considerably shorter life expectancy. This has a significant impact on both the economic and environmental performance of this vehicle. The life cycle emission analysis shows that, given the high fuel consumption of a conventional bus, the additional embedded CO2 emissions of the hybrid vehicles are offseted by the achieved reduction of in-service CO2 emissions due to fuel consumption reductions. Regarding the economic performance of the different platforms, results show that the fuel savings achieved by all hybrids displace the higher capital costs required. Overall, all hybrid buses show a strong potential to reduce both CO2 emissions and costs, resulting in negative costs of CO2 abatement.
Orbaiz, Pedro, van Dijk, Nicolás, Cosentino, Santiago, Oxenford, Nicolas, Carignano, Mauro, Nigro, Norberto Marcelo
Flexible, Water-Based Lithium-Ion BatteriesTBMG-287394/1/2018
Researchers have developed a lithium-ion battery that uses a water-salt solution as its electrolyte — reaching the 4.0- Volt mark for electronics such as laptops — without the fire and explosive risks associated with commercially available, non-aqueous lithium-ion batteries.
Energy Storage Thermal ManagementTBMG-281251/1/2018
A well-designed thermal management system is critical to the life and performance of electric-drive vehicles (EDVs), hybrids (HEVs), plug-in hybrids (PHEVs), and all-electric vehicles (EVs). Temperature and temperature uniformity both significantly affect the performance, lifespan, and safety of vehicle energy storage devices. NREL evaluates electrical and thermal performance of battery cells, modules, and packs, full energy storage systems, and the interaction of these systems with other vehicle components. The lab's performance assessments factor in the design of the thermal management system, the thermal behavior of the cell, battery lifespan, and safety of the energy storage system, as well as full integration into a vehicle.
Future Powertrain for Zero Emission Commercial Vehicles2017-01-19345/10/2017
In Japan, environmentally-friendly vehicles, such as HV, PHV, EV, and FCV, have been researched and developed as solutions to the energy and environmental problems, but none of these vehicles have been fully satisfactory in all respects, such as environmental performance, vehicle performance, and adaptability to existing infrastructure. Hino Motors, Ltd. launched a hybrid bus in 1992 as a pioneer in hybrid commercial vehicles and has sold more than 10,000 hybrid buses and trucks. An electric-powered minibus designed under the concept of short travel distance and high charging frequency was developed to make use of Hino’s abundant experience in the development of HV and the past market results it has achieved. Since 2012, these buses have operated in three areas as community buses. The capacity of the lithium-ion battery (LIB) was able to be minimized through the development of an energy management strategy that took into consideration the specific characteristics of the vehicle’s operation. This paper describes the technological development contents of an electric powertrain to realize the commercialization of zero emissions commercial vehicles that would be suitable for a use and utilize the existing infrastructure.
Sasaki, Takashi
Optimal Power Management of Vehicle Sourced Military Outposts2017-01-02713/28/2017
This paper considers optimal power management during the establishment of an expeditionary outpost using battery and vehicle assets for electrical generation. The first step in creating a new outpost is implementing the physical protection and barrier system. Afterwards, facilities that provide communications, fires, meals, and moral boosts are implemented that steadily increase the electrical load while dynamic events, such as patrols, can cause abrupt changes in the electrical load profile. Being able to create a fully functioning outpost within 72 hours is a typical objective where the electrical power generation starts with batteries, transitions to gasoline generators and is eventually replaced by diesel generators as the outpost matures. Vehicles with power export capability are an attractive supplement to this electrical power evolution since they are usually on site, would reduce the amount of material for outpost creation, and provide a modular approach to outpost build-up. Military vehicles have the attributes of a microgrid and when connected produce a scalable power generation capability [1]. For example, each vehicle could power a subset of the outpost’s build-up and when connected form a networked microgrid topology. However, vehicles must be available to disconnect dynamically for mobility-centric mission requirements. When this happens, there will likely be a shortage of electrical power requiring prioritized load shedding. Alternatively, excess generation will occur at times motivating an optimal solution to efficiently utilize the generation assets and minimize fuel consumption. An optimal, power management and control scheme is described using a notional 72-hour outpost evolution scenario to illustrate the approach. Particular attention is given to competing objectives such as minimizing fuel consumption while maintaining portable battery state-of-charge for equipment used during patrols. Using an optimal power flow and power coordination controller, vehicle centric microgrid architectures were constructed and simulated. For the uninterrupted outpost construction, the scheduled generation and storage were sufficient to supply all prioritized loads. Conversely, for the interrupted outpost construction, vehicle availability dictated which prioritized loads could be satisfied when unexpected power deficits arise.
Rizzo, Denise, Jane, Robert, Parker, Gordon G., Weaver, Wayne, Matthews, Ronald, Cook, Michael
An Improved Battery Modeling Method Based on Recursive Least Square Algorithm Employing an Optimized Objective Function2017-01-12053/28/2017
To monitor and guarantee batteries of electric vehicles in normal operation, battery models should be established primarily for the further application in battery management system such as parameter identification and state estimation including state of charge (SOC), state of health (SOH) and so on. In this paper, an improved battery modeling method is proposed which is based on the recursive least square (RLS) algorithm employing an optimized objective function. The proposed modified objective function not only includes the normal sum of voltage error squares between measured voltage and model output voltage but also introduces a new variable representing the sum of first order difference error squares for both kinds of voltages. This specialty can undoubtedly guarantee better agreement for the measured output and the model output. The battery model used in this paper is selected to be the conventional second order equivalent circuit model. Similar to the conventional RLS algorithm, the detailed deduced procedure and recursion formulae of the algorithm which are applicable online are respectively provided based on the proposed objective function. Moreover, to further balance the weight of the two items in the optimized objective function, a weight factor w is added and the corresponding recursion formulae are also derived. 8 Ah LiFePO4 batteries are chosen in the experiments for the validation of the proposed algorithms. The results of voltage outputs and errors generated from the proposed modeling algorithms are compared under the Urban Dynamometer Driving Schedule (UDDS) profile and the New European Driving Cycle (NEDC) profile with those of traditional RLS algorithm which validate the improvement of model performance and effectiveness of the proposed algorithms.
Zhu, Letao, Sun, Zechang, Wei, Xuezhe, Dai, Haifeng
The Battery Man SPEAKS16AUTP11_0211/1/2016
The speed of progress in automotive lithium batteries has impressed AABC's Dr. Menahem Anderman. So has silicon-graphite anode technology development from Tesla and Panasonic. The future of vehicle electrification is all about the battery. The industry's steady progress in reducing lithium-ion battery cost while increasing energy density, durability and reliability has surprised one of its leading experts, who is quick to admit a miscalculation he made six years ago. “Battery costs are coming down faster than I predicted-and faster than the major Japanese cell producers who have been my clients for many years predicted,” said Dr. Menahem Anderman, independent battery-industry consultant, founder of the well-known Advanced Automotive Battery Conference (AABC) series and frequent speaker at SAE's Hybrid & Electric Vehicle Symposia.
Brooke, Lindsay
Fuel-Optimal Strategies for Vehicle Supported Military Microgrids2016-01-03124/5/2016
Vehicles with power exporting capability are microgrids since they possess electrical power generation, onboard loads, energy storage, and the ability to interconnect. The unique load and silent watch requirements of some military vehicles make them particularly well-suited to augment stationary power grids to increase power resiliency and capability. Connecting multiple vehicles in a peer-to-peer arrangement or to a stationary grid requires scalable power management strategies to accommodate the possibly large numbers of assets. This paper describes a military ground vehicle power management scheme for vehicle-to-grid applications. The particular focus is overall fuel consumption reduction of the mixed asset inventory of military vehicles with diesel generators typically used in small unit outposts. By exploiting peak efficiency operation of the diesel generators and the vehicle’s energy storage systems, the total fuel consumption can be reduced over a typical daily outpost load cycle. While military vehicle energy storage requirements are dominated by silent watch objectives, this work adds another dimension to the objective set to include outpost fuel consumption. Motivated by these requirements, an extensible MATLAB/Simulink simulation of the system was constructed using the complex nodal admittance matrix approach to connect stationary diesel generators and vehicles with two-way power flow for either supporting the power grid or acting as a load for charging their batteries. After describing the model and energy management strategy, simulation studies are used to illustrate the approach using both idealized and measured outpost load data.
Jane, Robert S., Parker, Gordon G., Weaver, Wayne, Rizzo, Denise M.
Electric Vehicles Batteries Modeling Analysis Based on a Multiple Layered Perceptron Identification Approach2015-36-01429/22/2015
A reliable battery state estimation management system in electric vehicles greatly depends on the validity and generalizability of battery models. This paper presents a Li-ion and Lead Acid batteries neural model. This model does not consider battery details, bringing universality, which is suitable for parameters estimation of all battery kinds. The final model proposes describe the dynamic contributions due to open-circuit voltage, polarization time constants, electrochemical hysteresis, effects of temperature, state of charge and state of health.
dos Santos, Sender Rocha, de Sousa, Thais Tóssoli, de Tarso Peres, Paulo, de Fátima Negreli Campos Rosolem, Maria, França, Alex Pereira
Determining Remaining Useful Life for Li-ion Batteries2015-01-25849/15/2015
A high fidelity system for estimating the remaining useful life (RUL) for Li-ion batteries for aerospace applications is presented. The system employs particle filtering coupled with outlier detection to predict RUL. Calculations of RUL are based on autonomous measurements of the battery state-of-health by onboard electronics. Predictions for RUL are fed into a maintenance advisor which allows operators to more effectively plan battery removal. The RUL algorithm has been exercised under stressful conditions to assert robustness.
Dickerson, Andrew, Rajamani, Ravi, Boost, Mike, Jackson, John
Simulation of Lithium Ion HEV Battery Aging Using Electrochemical Battery Model under Different Ambient Temperature Conditions2015-01-11984/14/2015
This paper investigates the aging performance of the lithium ion cobalt oxide battery pack of a single shaft parallel hybrid electric vehicle (HEV) under different ambient temperatures. Varying ambient temperature of HEVs results in different battery temperature and then leads to different aging performance of the battery pack. Battery aging is reflected in the increasing of battery internal resistance and the decreasing of battery capacity. In this paper, a single shaft parallel hybrid electric vehicle model is built by integrating Automotive Simulation Model (ASM) from dSPACE and AutoLion-ST battery model from ECPower to realize the co-simulation of HEV powertrain in the common MATLAB/Simulink platform. The battery model is a physics-based and thermally-coupled battery (TCB) model, which enables the investigation of battery capacity degradation and aging. Standard driving cycle with differing ambient temperatures is tested using developed HEV model. The variation of capacity fading rate under different temperatures is observed. Under extreme temperature conditions, it is found that the range of the voltage response of the battery pack is wider under lower temperatures indicating an increase in internal resistance. The aging of the battery, observed from the decreasing of battery capacity, is also faster under lower temperature. The simulation results of this study provide useful information and reliable model for the effective design of HEV battery management systems.
Cheng, Ming, Feng, Lei, Chen, Bo
Development of Li-ion Battery Control Technology for HEV2015-01-02514/14/2015
The mounting of lithium-ion batteries (LIB) in hybrid electric vehicles (HEV) calls for the configuration of highly robust control systems. When mounting LIBs in the vehicle, it is important to accurately ascertain and precisely control the state of the battery. In order to achieve high durability, it is important to configure highly reliable systems capable of dependably preventing overcharging as well as to have control technology based on software that can contribute to extended battery life. The system configuration applies an overcharge prevention system that uses voltage detection with an emphasis on reliability. Furthermore, a method for varying the range of state of charge (SOC) control in the vehicle according to the battery state is implemented to assure durability. In order to achieve this, battery-state detection technology was developed for the purpose of correctly detecting and judging the battery state. This battery control system is able to enhance the durability while obtaining the maximum battery performance. This paper reports on the configuration of such systems, methods of state detection, and applications based on detection results.
Nishida, Yoshikazu, Komoda, Satoru, Maruno, Naoki
Li-Ion Battery Pack Characterization and Equivalent Electrical Circuit Model Development2014-01-18394/1/2014
This paper outlines the characterization of a Li-Ion Iron Phosphate battery pack with nominal voltage of 700V as well as the modeling of this pack as an equivalent electrical circuit (EEC) for the purpose of vehicle simulations. For a higher level of fidelity and accuracy, the equivalent circuit is initially modeled as an R-2RC circuit which consists of a voltage source with one resistor (R) and two resistor-capacitor (RC) branches. In this modeling effort, first, several open circuit voltage (OCV) determination methods in the literature are benchmarked and state-of-charge (SOC) dependent OCV curve which is used in the voltage source of the EEC model is derived. Then, two methods of parameter estimation of the EEC are developed for both step current and dynamic current profiles. The first estimation method is applicable to discharge or charge step currents and relies mostly on the relaxation portion of the battery response and involves some manual calibration. The second estimation method utilizes online parameter estimation techniques and learns the EEC parameters automatically by processing the battery response to some special designed dynamic current profiles. At the final stage, the battery model is validated against actual battery test results for a current profile experienced in a heavy duty vehicle drive cycle. According to these test results, the necessity of R-2RC models and the sufficiency of R-1RC or R models are elaborated for the purpose of vehicle simulations and some modifications are proposed and validated for the standard R-2RC battery EEC model.
Dagci, Oguz H., Chandrasekaran, Ram
Physics-Based Models, Sensitivity Analysis, and Optimization of Automotive Batteries2014-01-18654/1/2014
The analysis of nickel metal hydride (Ni-MH) battery performance is very important for automotive researchers and manufacturers. The performance of a battery can be described as a direct consequence of various chemical and physical phenomena taking place inside the container. In this paper, a physics-based model of a Ni-MH battery will be presented. To analyze its performance, the efficiency of the battery is chosen as the performance measure, which is defined as the ratio of the energy output from the battery and the energy input to the battery while charging. Parametric sensitivity analysis will be used to generate sensitivity information for the state variables of the model. The generated information will be used to showcase how sensitivity information can be used to identify unique model behavior and how it can be used to optimize the capacity of the battery. The results will be validated using a finite difference formulation.
Banerjee, Joydeep, McPhee, John, Goossens, Paul, Dao, Thanh-Son
Analytical Calibration of Map-Based Energy Managements of Parallel Hybrid Vehicles2014-01-19024/1/2014
Most energy management systems for hybrid electric vehicles still use rule-based energy management systems that rely on information stored in lookup tables, to define the current mode of operation and set-points for the low-level control laws. Because of the high number of parameters, the calibration of such energy managements can be a cumbersome task for the engineers. Mathematical tools are therefore inalienable to the calibration process. In this paper, it will be demonstrated, how the theory of hybrid optimal control can be used to calculate an initial parameter set for the energy management of charge-sustaining hybrids. The calculation procedure includes the solution of a hybrid optimal control problem to determine the controls for the optimal operation of the vehicle over a given cycle. The results can then be used to automatically calculate lookup-tables for optimal gear shifts, optimal torque-split between motor/generator and internal combustion engine and the determination of the drive mode (electric or hybrid mode).
Boehme, Thomas Juergen, Schori, Markus, Rabba, Heiko, Schultalbers, Matthias
Thermal Management Modeling for Avoidance of Thermal Runaway Conditions in Lithium-Ion Batteries2014-01-07074/1/2014
The emergence of Plug-in hybrid electric vehicles (PHEVs) and electric vehicles (EVs) as a viable means of transportation has been coincident with the development of lithium-ion battery technology and electronics that have enabled the storage and use of large amounts of energy that were previously only possible with internal combustion engines. However, the safety aspects of using these large energy storage battery packs are a significant challenge to address. For example an unintentional sudden release of energy, such as through a thermal runaway event, is a common concern. Developing thermal management systems for upset conditions in battery packs requires a clear understanding of the heat generation mechanisms and kinetics associated with the failures of Li-ion batteries. Although every effort is made to avoid thermal runaway situations, there can still be upset and unforeseen instances where a cell or a pack would reach a sufficiently high temperature to initiate exothermic reaction(s) that often are initially slow to develop. Properly designed thermal management systems should be able to lower pack temperatures, effectively slowing down or stopping these exothermic reactions. On the other hand, a poorly designed system could let the temperature rise to a point where a thermal runaway becomes inevitable. In this work, a framework for assessing the efficacy of a thermal management system is presented. In particular, the cells can be tested in an Accelerating Rate Calorimeter (ARC) in order to quantify the slow exothermic reactions that are typically the precursor to a thermal runaway event. Using the test data, numerical models of the cell or cell packs, along with its thermal management system, can be developed. Specifically, a three-dimensional (3D) computational fluid dynamics (CFD) model and an in-house one dimensional (1D) heat transfer model are proposed and their results compared. The paper shows how both the models are viable tools to simulate various thermal upset conditions and assess the performance of the thermal management in avoiding thermal runaway.
Ponchaut, Nicolas F., Colella, Francesco, Spray, Ryan, Horn, Quinn
Physics-Based Models, Sensitivity Analysis, and Optimization of Automotive Batteries2013-01-256010/14/2013
The analysis of nickel metal hydride (Ni-MH) battery performance is very important for automotive researchers and manufacturers. The performance of a battery can be described as a direct consequence of various chemical and physical phenomena taking place inside the container. In this paper, a physics-based model of a Ni-MH battery will be presented. To analyze its performance, the efficiency of the battery is chosen as the performance measure, which is defined as the ratio of the energy output from the battery and the energy input to the battery while charging. Parametric sensitivity analysis will be used to generate sensitivity information for the state variables of the model. The generated information will be used to showcase how sensitivity information can be used to identify unique model behavior and how it can be used to optimize the capacity of the battery. The results will be validated using a finite difference formulation.
Banerjee, Joydeep, McPhee, John, Goossens, Paul, Dao, Thanh-Son, ahn, Hyun-Doo
Failure Analysis of Some Toyota Prius Battery Packs and Potential for Recovery2013-01-256110/14/2013
The Toyota Prius battery pack consists of 38 individual battery modules, each module contains 6 NiMH cells in series. This means that each pack contains 228 NiMH cells. Each cell has the potential to fail. This report investigates the mode of failure of Prius battery packs by first analysing a number of packs in the lab, and then road testing them in a Toyota Prius. The analysis of the battery packs show that some packs had aged “linearly”, that is in a balanced manner, such that the state of health of all modules remained similar. However, in other packs discrete modules had significantly different states of health. A pack that consists of cells that are matched in both state of health and state of charge delivers the best performance. The research also showed that the worst cell in the pack determines the overall pack performance. This was demonstrated by substituting reduced capacity or short-circuited modules into a functioning battery pack. A vehicle with a pack consisting of 37 2400 mAh battery modules and one 1200 mAh battery module was only able to drive 1.3 km in Electric Vehicle mode, as opposed to 2.6 km with a pack consisting of 38 2400 mAh battery modules.
Leijen, Peter, Scott, Jonathan
Pulse Power Testing of Batteries and Supercapacitors for Hybrid Electric Vehicle Applications: A Comparison of Constant Current, Constant Power, and Ramped Power Transients2013-01-15354/8/2013
The central performance requirement for electrochemical energy storage systems for the full power-assist hybrid electric vehicle (HEV) is pulse power capability, typically 25-40 kW pulse power capability for 10 seconds duration. Standard test procedures utilize constant current pulses. However, in the HEV application, the power transient for acceleration is a ramped power transient and the power transient for regenerative braking power is a descending power ramp. This paper compares the usable power capability of batteries and supercapacitors under constant current, constant power, and ramped power transients. Although the usable battery discharge power is relatively insensitive to the transient type applied, 10-40% higher regenerative braking charge capability is observed with ramped power transients. With supercapacitors, the discharge and charge capability is much more strongly dependent on the type of power transient. The discharge power capability in a ramped power transient is 2.4 times that in a constant current pulse. The regen charge power capability is over 3 times that in a constant current pulse. Standard constant current test procedures thus underestimate the power capability of supercapacitors for HEV applications by several-fold. Supercapacitors provided over 2500 W/kg usable power for HEV applications, exceeding that of high power nickel metal hydride and lithium ion batteries tested.
Corrigan, Dennis A., Liu, Xiao
SAE Electrical Energy Storage Device Labeling Recommended PracticeJ2936_201212 (Current)12/7/2012
This SAE Recommended Practice provides for labeling guidelines at all levels of component, subsystem and system level architectures describing content, placement and durability requirements of specific unit throughout the total product life cycle from inception to reclamation.
Battery Tape and Label Committee
Mobile Hybrid Power System's Elements2012-01-223610/22/2012
The effectiveness of elements comprising a hybrid electric power generating system was studied. The wind and photovoltaic renewable resources served as integral components of the hybrid systems configuration. A HMMWV towable trailer system provided an intermediary basis for formulation of methodology needed for optimization of power generation and energy storage capacity constrained by cost, size and weight of the system. The methodology employed in this paper is scalable from kilowatts to megawatts or from man portable systems to significantly larger systems which can be housed in 40 foot ISO containers.
Dawidowicz, Edward, Podlesak, Thomas, Leung, Fee
Electrical Energy Storage to Meet Evolving Aircraft Needs2012-01-219910/22/2012
The value of “ultracapacitors” (also referred to as “supercapacitors” or “electric double layer capacitors” in some literature) as an augmentation device when placed in parallel with “electrochemical” energy storage (i.e. battery) is presented in this paper. Since ultracapacitors possess unique attributes due to their higher value of energy storage density (or Joules/WattHrs per mass) compared to conventional capacitors while maintaining the peak power providing capability (to some degree) typical of conventional capacitors they may provide a near term solution in applications demanding longer battery operating life when placed in parallel. Such demands may be pronounced by the onset of More-Electric-Aircraft peak loads and “cold-crank” Auxiliary Power Unit (APU) electric-starting in demanding cold temperature environments. The potential benefits of an ultracapacitor in parallel with a battery will be illustrated through a very simple lab demonstration as well as a more complex system consisting of a large motor inrush load (cold-cranking condition) through the use of a computer simulation tool (Simulink). In addition to the ultracapacitor discussions and demonstration, other forms of advanced energy storage will be reviewed for their potential near or long term application in meeting the evolving needs of More Electric Aircraft as presented at the 2011 International Double Layer Capacitor and Hybrid Energy Storage Seminar in Deerfield Beach Florida (Reference 3).
Brewer, Roger
Impact of Auxiliary Loads on Fuel Economy and Emissions in Transit Bus Applications2012-01-10284/16/2012
In this paper we present the results of full-scale chassis dynamometer testing of two hybrid transit bus configurations, parallel and series and, in addition, quantify the impact of air conditioning. We also study the impact of using an electrically controlled cooling fan. The main trend that is noted, and perhaps expected, is that a significant fuel penalty is encountered during operation with air conditioning, ranging from 17-27% for the four buses considered. The testing shows that the series hybrid architecture is more efficient than the parallel hybrid in improving fuel economy during urban, low speed stop and go transit bus applications. In addition, smart cooling systems, such as the electrically controlled cooling fan can show a fuel economy benefit especially during high AC (or other increased engine load) conditions. The series hybrid bus was equipped with an active Diesel Particulate Filter (DPF); the filter was found to be in active mode during the AC-on tests, which adversely impacted the fuel economy. The DPF operation prevented a direct comparison of the series and parallel hybrids with AC-on. Some interesting features of the active DPF were noted during operation; these included an increase in hydrocarbon emissions during active regeneration with the main hydrocarbon being methane. In contrast, unburned diesel fuel was the primary hydrocarbon constituent during standard operation (i.e., passive DPF or DOC).
Muncrief, Rachel L., Cruz, Miguel, Ng, Henry, Harold, Michael
GE Electric Drivetrain Technologies for Lightweight Battery Dominant Hybrid Fuel Cell Bus2012-01-10294/16/2012
Aside from the fuel cell prime mover, the drivetrain elements of a fuel cell hybrid transit bus are those of a heavy-duty series hybrid vehicle. The U.S. National Fuel Cell Bus Program is advancing all aspects of fuel cell transit bus technology, including fuel cells and other electric drivetrain technologies. Key electric drivetrain technologies developed by General Electric (GE) in the Lightweight Battery-dominant Hybrid Fuel Cell Bus project, their integration to the vehicle design, together with the vehicle build and demonstration plans are described. The GE technologies are sodium metal halide energy batteries, the dual battery energy storage system, energy management controls and dc-dc converter power electronics. Further electric drive vehicle technology developments focused on the fuel cell transit bus application are proposed.
Salasoo, Lembit, Richter, Tim, King, Robert D, Li, Zhihao
The Flexible EV/HEV and SOC Band Control Corresponding to Driving Mode, Driver's Driving Style and Environmental Circumstances2012-01-10164/16/2012
Recently, in accordance with the increased interest of consumer in fuel efficiency due to the phenomenon of high oil price, complaints against actual fuel efficiency in the road in comparison with the certified fuel efficiency have been raised frequently. Especially in case of the hybrid vehicle which is highly popular for the reason of its high fuel efficiency compared with that of existing gasoline car, deviation in the fuel efficiency will be higher compared with that of gasoline car in accordance with the driving mode (downtown/highway), driver's driving style (wild/mild) and external environmental condition (gradient/temperature/altitude). To solve them, this paper developed a method so that the SOC (State Of Charge), EV/HEV mode transition point can be controlled variably in accordance with the driving mode, driver's driving style and external environmental condition by making the most of characteristics of hybrid. Through it, efficient engine operating point could be secured even in the driving situation under severe condition while maintaining a stable SOC value, and it was verified that there are effects of increases in the average fuel efficiency and reduction of deviation in the fuel efficiency (about 5.9 mpg, 10∼20%) among vehicles through HILS (Hardware-In-the-Loop-Simulation) validation. Application of this developed logic to 12 MY YF/TF hybrid vehicles of HYUNDAI MOTORS has been completed.
Kim, Jeongeun, Sim, Hyunsung, Oh, Jonghan
Concepts for Mechanical Abuse Testing of High-Voltage Batteries2012-01-01244/16/2012
Currently lithium-batteries are the most promising electrical-energy storage technology in fully-electric and hybrid vehicles. A crashworthy battery-design is among the numerous challenges development of electric-vehicles has to face. Besides of safe normal operation, the battery-design shall provide marginal threat to human health and environment in case of mechanical damage. Numerous mechanical abuse-tests were performed to identify load limits and the battery's response to damage. Cost-efficient testing is provided by taking into account that the battery-system's response to abuse might already be observed at a lower integration-level, not requiring testing of the entire pack. The most feasible tests and configurations were compiled and discussed. Adaptions of and additions to existing requirements and test-procedures as defined in standards are pointed out. Critical conditions that can occur during and after testing set new requirements to labs and test-rigs. A ‘thermal runaway’ may emerge from a mechanical-induced short-cut, resulting in an extreme raise in temperatures, outgassing, smoke, fire and, under adverse conditions, explosions. Potentially critical situations and safety hazards were compiled, supporting labs in mitigating and averting hazardous situations. Existing safety concepts and evacuation strategies are outlined, reducing the hazards of battery testing.
Sinz, Wolfgang, Feist, Florian, Gstrein, Gregor, Gugler, Jürgen, Tomasch, Ernst, Breitfuss, Christoph, Luttenberger, Peter, Steffan, Hermann, Gollob, Peter, Hennige, Volker
Comparison of Plug-In Hybrid Electric Vehicle Battery Life Across Geographies and Drive Cycles2012-01-06664/16/2012
In a laboratory environment, it is cost prohibitive to run automotive battery aging experiments across a wide range of possible ambient environment, drive cycle, and charging scenarios. Because worst-case scenarios drive the conservative sizing of electric-drive vehicle batteries, it is useful to understand how and why those scenarios arise and what design or control actions might be taken to mitigate them. In an effort to explore this problem, this paper applies a semi-empirical life model of the graphite/nickel-cobalt-aluminum lithium-ion chemistry to investigate calendar degradation for various geographic environments and simplified cycling scenarios. The life model is then applied to analyze complex cycling conditions using battery charge/discharge profiles generated from simulations of plug-in electric hybrid vehicles (PHEV10 and PHEV40) vehicles across 782 single-day driving cycles taken from a Texas travel survey. Drive cycle statistics impacting battery life are compared to standard test cycles.
Smith, Kandler, Earleywine, Matthew, Wood, Eric, Neubauer, Jeremy, Pesaran, Ahmad
Advanced Silicon Anode technology for high performance LI-ION BatteriesTP-AAB-0024/3/2012
Lithium ion batteries are the state-of-the-art rechargeable power sources and have been widely used not only for portable equipment such as cellular phones, personal computers and digital cameras, but also power tools and industrial applications like robot and electric vehicles. The battery capacity has doubled since its commercialization in the early 1990s with the improvement of material and battery technologies, without changing the basic concept and its chemistry. Recently we have seen this improvement slow, approaching the theoretical limit of the system. A new battery system is necessary to meet the rigorous demands of energy and power increments for the progress of high and multi-functional mobile equipments and to secure the sufficient mileage of an electric vehicle per charge. Under these circumstances, alloy anode materials are expected to be promising candidates to remarkably increase the capacity of lithium ion batteries. In this presentation, the potential and benefits of silicon anode material and recent breakthroughs that have been achieved are introduced.
Yasuda, Kiyotaka
Development of Electric Motorcycle for Business Use2011-32-055611/8/2011
In recent years, the reduction of CO₂ emissions is under way, and the expectancy for electrical power is getting bigger for motorcycles as well. This time, an electric motorcycle with good driving performance, adequate range and quick charging performances for business use has been developed using a small battery. The travel modes have been investigated for business applications of delivery services to classify the traveling patterns and the objectives have been settled based on them. The energy efficiency has been improved by the application of the smallest amount of battery and by the integrated power unit configuration. With this achievement, the range of 34 km (at a constant speed of 30 km/h) has been realized while maintaining the 12-degree hill-climbing departure performance when loaded with a rider and a 30 kg load, which is the requirement of performance for business use. Moreover, the charging and discharging are controlled by the battery monitoring system which enables both driving and charging operations in temperatures from -10°C to 35°C to satisfy the requirement for business use. In addition, a quick charger with two-step charging current control, which can charge from 0% to 80% State of Charge (hereafter SOC) within 20 minutes, has been developed.
Cho, Toshiyuki, Akiba, Ryuji, Sone, Takashi
Concept of an Urban Family Electric Vehicle2011-36-030110/4/2011
In over one hundred years of history and engineering development vehicles, prevailed the internal combustion engine. Automotive technology evolution has overcome obstacles to socioeconomic and geographical expansion of the common usage and access to motorized vehicles. Technological solutions have been created for many different vocations and vehicular applications. Electric vehicle initiates threshold of a new cycle of product development and technologies. Thus, the electric vehicle brings to discussion central issues, such as, application, vehicle operation cycle, comfort, safety, performance, technological choices, efficiency, lifecycle and cost. These questions expand to manufacturing technology, logistics and after-sales. And these take to outermost, but nonetheless relevant, questions of infrastructure, user culture and new paradigms for the coexistence between humans and the technological equipment. This paper proposes to study within the framework of the central questions, which are the main characteristics of a family electric vehicle for urban application. In this exploratory qualitative research, the primary data has been obtained through interviews with specialists in electric vehicles at a car manufacturer, in Tokyo in Japan. It has been adopted a baseline car, an electric battery vehicle, to test drive and analysis of characteristics of electric-vehicle - targeted towards the focus of this research. The study has chosen this vehicle with no prejudice of value to others who are present in this technology race. The secondary data has been obtained through product folders and internet site of the company. The search result contributed to characterize a urban family electric vehicle and has concluded: 1. The model studied has as one of the main characteristics a satisfactory autonomy for urban commuting before a battery recharge is needed; 2. The infrastructure for the use of fully electric model needs advance faster in order to meet vehicles demand in near future.
Albertin, José Luiz, Jussani, Ailton Conde
Introduction of 2011 CIVIC Hybrid system2011-01-17488/30/2011
Technologies related to electrical systems for the 2011 hybrid model have been developed. In order to increase energy recovery during driving, improvements were made compared to the 2006 model in terms of motor output increase and high-efficiency range expansion. In consideration of vehicle control associated with the use of lithium-ion batteries (LIBs) as well as reliability, a system to control effective use of battery performance was developed which involves detection of battery conditions. Control of energy management was optimized compared to nickel metal hydride (NiMH) batteries through the use of higher-output LIBs and a high-output motor.
Saito, Takeshi, Fukui, Takahiro
Ultracapacitor-Based Uninterrupted Power Supply SystemTBMG-101336/1/2011
The ultracapacitor-based uninterrupted power supply (UPS) system enhances system reliability; reduces life-of-system, maintenance, and downtime costs; and greatly reduces environmental impact when compared to conventional UPS energy storage systems. This design provides power when required and absorbs power when required to smooth the system load and also has excellent low-temperature performance. The UPS used during hardware tests at Glenn is an efficient, compact, maintenance-free, rack-mount, pure sine-wave inverter unit.The UPS provides a continuous output power up to 1,700 W with a surge rating of 1,870 W for up to one minute at a nominal output voltage of 115 VAC. The ultracapacitor energy storage system tested in conjunction with the UPS is rated at 5.8 F. This is a bank of ten symmetric ultracapacitor modules.
Development of Hybrid System for 2011 Compact Sedan2011-01-08654/12/2011
Technologies related to electrical systems for the 2011 hybrid model have been developed. In order to increase energy recovery during driving, improvements were made compared to the 2006 model in terms of motor output increase and high-efficiency range expansion, and considerations were also given to motor NV (noise and vibration). In consideration of vehicle control associated with the use of lithium-ion batteries (LIBs) as well as reliability, a system to control effective use of battery performance was developed which involves detection of battery conditions. Control of energy management was optimized compared to nickel metal hydride (NiMH) batteries through the use of higher-output LIBs and a high-output motor.
Fukui, Takahiro, Saito, Takeshi
Thermal Behavior Study on HEV Air-Cooled Battery Pack2011-01-13684/12/2011
Recently, an increased emphasis has been seen for improving the cooling uniformity and efficiency of HEV battery pack in an effort to increase the battery performance and life. This study examined the effects of geometry changes in cooling systems of battery packs on thermal behavior of battery cells and pressure drop across the battery pack. Initially, a multi-physics battery thermal model was correlated to physical test data. An analytical design of experiments (DOE) approach using Latin-hypercube technique was then developed by integrating the correlated battery thermal model with a commercial optimization code, iSIGHT, and a morphing code, DEP Morpher. The design concepts of battery pack cooling systems were finally identified by performing analytical DOE/optimization studies to estimate the effects of cooling flow and geometries of cooling ducts on the battery temperature variation and pressure drop across the battery pack.
Sun, Hongguang, Tossan, Brian, Brouns, Daniel
Experimentally-Determined Models for High-Power Lithium Batteries2011-01-13654/12/2011
Lithium batteries are increasingly being considered for installation as power sources in electric and hybrid vehicles, because of their high specific energy and power. To effectively size the vehicle Rechargeable Energy Storage System, it is very important to be able to mathematically model their behaviour. Battery modelling is also very useful for on-line management of electric and hybrid vehicles. This paper presents a dynamic model of lithium batteries based on experimental tests on high power Lithium-polymer models. The results can be adapted, with suitable parameter evaluation, to other lithium batteries as well.
Ceraolo, Massimo, Lutzemberger, Giovanni, Huria, Tarun
Development of Lithium-Ion-Battery System for Hybrid System2011-01-13724/12/2011
A battery module structure and a battery management system that is optimal for the structure were developed, in order to facilitate the work of equipping hybrid cars with lithium-ion batteries (LIBs) that are expected to improve vehicle performance. This paper describes the structure of the LIB and the battery management system that is optimal for it. The battery module structure has cells with a sturdy holding structure and a highly efficient cooling system. The structure has enabled the improvement of battery pack system power output by 80% per unit weight and by 20% per unit volume compared to the previous model. The optimal management system prevents battery overcharge by detecting and controlling the state of charge (SOC) of each cell with a high degree of accuracy.
Oguri, Kosuke, Maruno, Naoki
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