Battery Management Systems

Battery Management Systems Universal State-of-Charge indication for portable applications describes the field of State-of-Charge (SoC) indication for rechargeable batteries. With the emergence of battery-powered devices with an increasing number of power-hungry features, accurately estimating the battery SoC, and even more important the remaining time of use, becomes more and more important. Therefore, many leading semiconductor companies, e.g. NXP Semiconductors, Texas Instruments, Microchip, Maxim, are paying an increasing amount of attention to accurate SoC and remaining run-time indication. An overview of the state-of-the-art of SoC indication methods and of the available market solutions is given in the first part of this book. Furthermore, the remainder of the book is dedicated to developing a universal SoC indication system with the final aim to predict the SoC and the remaining run-time with an accuracy of 1% or better under all realistic user conditions. For enabling this aim accurate measurement and modeling methods for the battery behaviour are developed. The obtained models are further combined with on-line predictive and adaptation solutions in a new SoC indication system. This latter aspect is important in order to take the battery aging process into account and to make the algorithm universally applicable to a range of battery chemistries. The obtained results prove the capability of the developed SoC system to offer an accurate and universal SoC indication system. A possible implementation of the SoC system together with a newly developed ultra-fast recharging algorithm on a mobile phone platform is also described. The contents of Battery Management Systems Universal State-of-Charge indication for portable applications builds further on the contents of the first volume in the Philips Research Book Series, Battery Management Systems Design by Modelling. Since the subject of battery SoC indication requires a number of disciplines, this book covers all important disciplines starting from (electro)chemistry to understand battery behaviour, via mathematics to enable modeling of the observed battery behaviour and measurement science to enable accurate measurement of battery variables and assessment of the overall accuracy, to electrical engineering to enable an efficient implementation of the developed SoC indication system. It will therefore serve as an important source of information for any person working in engineering and involved in battery management.