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Lithium-ion batteries are characterized by having very good performance in terms of efficiency, lifetime, and self-discharge, which allowed them to become the major player in the electric vehicle applications. However, they were not able to totally overcome the EV range anxiety. Thus, research is carried out nowadays to develop batteries with even higher gravimetric energy density, which should allow...
The paper presents a modelling approach which, starting from experimental measurements, allows automatically deriving a lithium-ion battery electrical model. This procedure is applied to a 47.7 kW lithium-manganese oxide battery unit in order to infer a third-order Thevenin equivalent electrical model of the unit itself. By means of a matrix representation of specific experimental measurements, it...
Battery energy capacity in an application system is determined by the amount of electrical energy spent to the load and time consumption. The system reliability depends on the supply of electrical energy from the battery as the power source. The energy capacity of the battery will ensure the services provided by the unit device or equipment. As an example, the UPS system provides clean, conditioned,...
In order to analyze the dynamic behavior of a Lithium-ion (Li-ion) battery and to determine their suitability for various applications, battery models are needed. An equivalent electrical circuit model is the most common way of representing the behavior of a Li-ion battery. There are different circuit models proposed and various techniques for parameterization of these models available in literature...
A virtual measurement system has been developed in LabView environment for testing the main characteristics of photovoltaic (PV) modules. The survey was conducted with an autonomous PV system, built of two modules - one stationary and the other tracking the position of the Sun. Using the virtual measurement system are recorded the temperature of PV modules, the levels of generated current and voltage,...
In this experiment-based research, the performance and behaviour of a pouch type Li-ion battery cell are reported. The commercial test cell has a Lithium Titanate Oxide (LTO) based anode with 13Ah capacity. It is accomplished by measuring the evolution of surface temperature distribution, and the heat flux of the battery cell at the same time. Temperatures on the surface of the cell are measured using...
Constant current-constant voltage (CC-CV) charging and pulse current charging are the usual methods for charging Li-ion batteries. Because we are lack of the direct in-situ measurement of Li-ion battery's internal state, both of the two charging methods are controlled without feedbacks from inside of the battery. A new charging method is proposed in this paper based on electrochemical-thermal coupling...
This paper deals with the use of Lithium Batteries at high pulses discharge rate. The use of a commercial nanophosphate-based ultra high power Li-Ion cell discharged by high current pulses is analyzed by means of an ad — hoc experimental setup. Main cell parameters like nominal capacity, internal impedance, discharge efficiency are measured and discussed. An ad — hoc test procedure and a new strategy...
This paper adopts a circuit model with temperature-dependent parameter values to investigate the current unbalance risk in parallel-connected lithium-ion (Li-ion) battery cells and uses this circuit model to calculate heat dissipation. The paper first investigates use of the battery model to explain the impact of temperature on current unbalance in parallel-connected Li-ion battery cells. Experimental...
In this paper, an automated battery test bench is proposed. The proposed bench consists of circuit breaker unit, uninterruptible power supply unit, system load unit, twelve battery research channels, distribution device, heat chamber, computerized control measuring device and communication device. The bench allows to perform thermal, resource and electrical tests of several lithium-ion batteries simultaneously...
In this paper, an automated battery test stand is proposed. The proposed stand consists of circuit breaker unit, uninterruptible power supply unit, system load unit, twelve battery research channels, distribution device, heat chamber, computerized control measuring device and communication device. The stand allows to perform thermal, resource and electrical tests of several lithium-ion batteries simultaneously...
Today, battery electric vehicles as well as stationary battery system demand lithium-ion batteries. Lithium titanate battery cells with their excellent charge and discharge rate capabilities in combination with their long lifetime have become an attractive option for these kinds of applications. However, to ensure safe operation of lithium batteries — especially in high power applications — temperature...
The operating temperature has a significant impact on the performance of electrochemical systems such as batteries. The amount of energy stored inside depends largely on the temperature (especially under 0°C). To maintain a good energy performance of the electric vehicle, it is necessary to know the parameters that characterize the battery to allow a better approximation of the amount...
Lithium-ion (Li-ion) batteries are found nowadays not only in portable/consumer electronics but also in more power demanding applications, such as stationary renewable energy storage, automotive and back-up power supply, because of their superior characteristics in comparison to other energy storage technologies. Nevertheless, prior to be used in any of the aforementioned application, a Li-ion battery...
To estimate state-of-charge (SOC) and state-of-health (SOH) of a lithium ion battery as exact as possible, the terminal voltage, the terminal current and the cell temperature have to be measured. The easiest model of a battery is an ohmic-capacitive (R-C) series-parallel circuit. Two measurement methods are shown how to get ready to estimate SOC and SOH in a simple but precise manner. The first measurement...
Modern lithium-ion batteries, like LiMO2/Li4Ti5O12 chemistry, are having very high power capability, which drives the need for precise thermal modelling of the battery. Battery thermal models are required to avoid possible safety issues (thermal runaways, high-temperature gradients) but also for the optimal battery pack design and for predicting battery electrical performance during operation (especially...
Batteries are the most practical energy storage for mobile electrical devices. Aiming for more efficient battery systems results in new challenges for developers and scientists. Equipping a mobile device with an adequate battery typically requires an accurate model about the battery's behavior. To establish good models, precision measurements are necessary. In this paper we describe the development...
The goal of this paper is to describe the key methods for state of charge estimation. The presented techniques are current counting method, open circuit voltage and battery internal resistance method. This paper describes these methods and compares their accuracy.
This paper describes a time-domain approach for estimating the state of health (SOH) and remaining useful life (RUL) of a battery, with particular emphasis on LiFePO4 cells. In this methodology, a small test signal is superimposed on top of the battery load to trigger its transient dynamics. The resulting terminal voltage and current are measured, and a nonlinear least-squares routine is used to estimate...
The open circuit voltage (OCV) characterization of Li-ion batteries as it applies to battery fuel gauging (BFG) in portable applications is considered in this paper. Accurate knowledge of the nonlinear relationship between the OCV and the state of charge (SOC) is required for adaptive SOC tracking during battery usage. BFG in portable applications requires this OCV-SOC characterization to be defined...
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