The inconsistent characteristics of individual power batteries in a battery pack can seriously affect the performance and service life of the whole pack. Battery grouping is an effective approach for dealing with the inconsistency problem by grouping batteries with similar characteristics in the same battery pack. In actual production, the battery grouping process still relies on the traditiona...

Among various issues that high power application lithium-ion (Li-ion) batteries are encountered, thermal issues have received more attention because of their potential to degrade battery performance. In the present work, a lumped capacitance heat transfer model was developed in conjunction with a flow network approach to investigate thermal performance of a commercial-size Li-ion battery pack u...

Based on a low cost multi-switched inductor balancing circuit (MSIBC), a fuzzy logic (FL) controller is proposed to improve the balancing performances of lithium-ion battery packs instead of an existing proportional-integral (PI) controller. In the proposed FL controller, a cell’s open circuit voltages (OCVs) and their differences in the pack are used as the inputs, and the output of the FL con...

In order to safely and efficiently use the power as well as to extend the lifetime of the traction battery pack, accurate estimation of State of Charge (SoC) is very important and necessary. This paper presents an adaptive observer-based technique for estimating SoC of a lithium-ion battery pack used in an electric vehicle (EV). The RC equivalent circuit model in ADVISOR is applied to simulate ...

In this paper, the development and optimization of Power Distribution Control Strategy (PDCS) have been performed for a Hybrid Energy Storage Systems (HESS) of a Series Hybrid Electric Bus (SHEB). A common PDCS is based on the use of Ultra-Capacitor (UC) pack. A new simple PDCS is developed as a battery based one. For the battery based PDCS, four parameters ar...

The battery management system (BMS) of a hybrid-electric-vehicle (HEV) battery pack comprises hardware and software to monitor pack status and optimize performance. One of its important functions is to execute algorithms that continuously estimate battery state-of-charge (SOC), state-of-health (SOH), and available power. The accuracy of these algorithms is critical for the proper sizing of the ...

Battery management systems in hybrid-electric-vehicle battery packs must estimate values descriptive of the pack’s present operating condition. These include: battery state-of-charge, power fade, capacity fade, and instantaneous available power. The estimation mechanism must adapt to changing cell characteristics as cells age and therefore provide accurate estimates over the lifetime of the pac...

The goal of this work is to develop an efficient numerical modeling method for the vibration of hybrid electric vehicle (HEV) battery packs to support probabilistic forced response simulations and fatigue life predictions. There are two important sources of variations in HEV battery packs that affect their structural dynamic response. One source is the uncertain level of pre-stress due to bolts...

This application note discusses some of the hardware and software design decisions and shows how to select external components for a multi-cell Li-ion battery pack using a microcontroller and the ISL9208 analog front end. A microcontroller provides the primary control of the operation of the battery pack. However, several factors in the multi-cell series Li-ion pack require the use of circuitry...