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In stable electrical networks, such as the German one, the service of uninterruptible power supply (UPS) systems is only rarely called. Consequently the battery lifetime in this application is mostly restricted by calendar aging. The concept of multi-use describes here the delivery of additional services with a UPS during stable grid operation. The overall goal is to allocate the battery capacity...
The paper describes the aging behavior of the NMC/LTO li-ion cell using impedance model of the cell when cycled at different operating conditions. Paper depicts change in impedance with state of charge and cycle life. Both, solution and charge transfer, resistances increase at different stages of battery life. Change is Solution resistance (R1) is impacted by electrolyte decompositions as it changes...
Modern systems of traditional and alternative energy, transport systems include powerful uninterruptible power supplies (UPS), implemented on batteries of charged electrochemical current sources — accumulators. These modules ensure the functioning of the systems in case of accidents or technological failures in the operation of main power supplies. The ability to provide the given energy modes by...
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 achieve electrochemical cycling at high rates for batteries with improved power densities, battery electrodes need to support the efficient insertion / extraction of both, electrons and intercalation ions within their constituent material systems. This paper presents an on-chip, single nanowire electrochemical device for measuring the electrical properties of a battery nanoelectrode as...
The presented paper introduces a sensor minimal battery observer, which allows the equipping of each stack with only one voltage and one current sensor, without losing the required individual cell measurement. The individual cell measurement is required not only for many Li-Ion applications with cell chemistry that can result in exothermic reactions. For a stack with 12 cells this can results in a...
This paper provides importance of stationary VRLA battery health measurement system in critical energy storage applications. Factors affecting battery health and role of battery internal resistance on capacity loss are detailed. A comparison of different test methods used for health estimation in present industry is tabulated. Resistance estimation by dc method and ac methods are simulated and tested...
The most recent GreenTeam race car, the E0711-7, has been designed and built to set a new level of high performance race cars made by GreenTeam. This paper investigates the E0711-7's high performance powertrain design process, powertrain structure and the unique oil-cooled battery pack. Experimental results from test bench measurements and race data have been reported to illustrate the powertrain...
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...
Lithium-ion batteries are regarded as the key energy storage technology for both e-mobility and stationary renewable energy storage applications. Nevertheless, the Lithium-ion batteries are complex energy storage devices, which are characterized by a complex degradation behavior, which affects both their capacity and internal resistance. This paper investigates, based on extended laboratory calendar...
This paper proposes a robust, intelligent constant current-constant voltage (CC-CV) charger for fast charging an aging Lithium-ion battery. Increasing the charging current in the CC regime cannot guarantee the short charging time, so an optimal charging current exists in the CC-CV method. The optimal charging current changes with battery degradation, so this paper figures out a way to find the optimal...
In hybrid vehicles, lithium-ion cells constituting a battery pack are frequently used to provide and recover high power to assist the vehicle's internal combustion engine (ICE) powertrain. This usage is more present in mild hybrid applications where the battery does not have long discharge time. Under such conditions, the pack's series resistance ${R}_{S}$ proved to be an important parameter to monitor...
Based on the single point of failure model, the paper aims to provide a new detection method for insulation resistance of electric vehicle battery pack and present the principle analysis the deriving equations. By comparing the measurement results through the associated national standards of the People's Republic of China, i.e. GBT 18384.1-2001 for electric vehicles insulation resistance, discusses...
Due to the small ohmic resistance, such as the LFP battery, off-line state-of-health (SOH) estimation based on ohmic techniques faces a great challenge on measurement difficulty. The inaccurate measurement result of the ohmic resistance can cause a severe SOH error. This paper studies the influences of battery external resistance on the off-line SOH estimations using different model parameters in...
A long-term operation test of electric buses on public roads was performed in Nagano as part of a project of the Japan Ministry of the Environment from 2011 to 2014. For this project the short-range frequent- charging type electric buses, "Waseda Electric Buses (WEBs)" were developed. WEB-3, one of the test vehicles, was driven for 41,724 km without any major problems and had advantages...
Most recent studies on prognostics and remaining useful life (RUL) estimation for engineering systems are based on the underlying assumption that there is only one degradation / failure mechanism inherent in the system that is being tracked. This is often an overly simplistic assumption as systems in general are complex enough to be subject to degradation by multiple mechanisms that have different...
This paper addresses the effect of replacing damaged cells in a battery pack on the total State-of-Health (SoH) using a new technique in where the SoH of a Li-Ion battery pack is accurately determined. The new method is based on relating the parameters of a single-cell battery to determine the SoH in a multi-cell battery pack of the same type. This technique is applicable to the battery pack as it...
The battery state of charge (SOC) is an important parameter of the battery capacity state. It can only be indirectly estimated through measurable variables such as voltage, current and temperature. Accurate estimation of SOC is one of the key problems in a battery management system. A battery model based on equivalent electrical circuits has been used to describe the battery dynamics. The model has...
Internal resistance is an important element for lithium-ion batteries in battery management system (BMS) for battery energy storage system (BESS). The internal resistance consists of ohmic resistance and polarization resistance. Neither of them can be measured directly and they are identified by some algorithms with battery charging/discharging experiment data. In this paper, several 10Ah LiFePO4...
The battery management system (BMS) is an important component of electric and hybrid-electric vehicles. The purpose of the BMS is to keep the battery operation safe and reliable. Fuzzy logic system (FLS) is one of the methods used to maintain the safety and reliability of the battery by state monitoring and evaluation, charge control, and cell balancing in BMS. Fuzzy logic data analysis were used...
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