State-of-the-art of battery state-of-charge determination

Abstract

From the early days of its discovery, humanity has depended on electricity, a phenomenon without which our technological advancements would not have been possible. With the increased need for mobility, people moved to portable power storage—first for wheeled applications, then for portable and finally nowadays wearable use. Several types of rechargeable battery systems, including those of lead–acid, nickel–cadmium, nickel–metal hydride, lithium ion and lithium-ion polymer exist in the market. The most important of them will be discussed in this review. Almost as long as rechargeable batteries have existed, systems able to give an indication about the state-of-charge (SoC) of a battery have been around. Several methods, including those of direct measurements, book-keeping and adaptive systems (Bergveld et al 2002 Battery Management Systems, Design by Modelling (Philips Research Book Series) vol 1 (Boston: Kluwer)) are known in the art for determining the SoC of a cell or battery of cells. An accurate SoC determination method and an understandable and reliable SoC display to the user will improve the performance and reliability, and will ultimately lengthen the lifetime of the battery. However, many examples of poor accuracy and reliability can be found in practice (Bergveld et al 2002, cited above). This review presents an overview on battery technology and the state-of-the-art of SoC methods. The goal of all the presented SoC indication methods is to design an SoC indication system capable of providing an accurate SoC indication under all realistic user conditions, including those of spread—in both battery and user behaviour, a large temperature and current range and ageing of the battery.

Design, Implementation and Testing of an Automatic Power Management System for Residential Stand-alone Microgrids with Hybrid Power Supply

“…Several SOC models have been proposed in the literature (e.g., Piller, et al, 2001, Pop, et al, 2005, which can be grouped in the following categories: i) measurement of electrolyte specific gravity, ii) battery current time-integration, iii) battery impedance/resistance estimation, iv) measurement of the battery open circuit voltage, v) models that take into account the electrolyte temperature, discharge rate and other batteries parameters. Additionally, an accurate SOC estimation needs to take into account the battery environmental conditions, with particular reference to its temperature, as well as the battery behaviour at different discharge rates.…”

Advances in Electrochemical Models for Predicting the Cycling Performance of Traction Batteries: Experimental Study on Ni-MH and Simulation

“…Numerous approaches have been studied to monitor the State-of-Charge (SoC) of a cell [3,4]. The coulomb-counting procedure is not reliable for a precise SoC determination in traction batteries since not all current supplied goes to charging the cell and the charge lost to any undesired charge reaction is not included.…”

Estimativa do estado de carga de baterias em robôs móveis autônomos

“…Os tipos mais comum e comercialmente disponíveis são as baterias zinco-carbono e as alcalinas, (Figura 2). O quadro 2, mostra dados comparativos entre as baterias comercialmente mais utilizadas, dados compilado em [47], fabricantes e informações de mercado. Corrente de carga …”

“…A seguir algumas definições e termos relacionados a baterias normalmente usadas pelas indústrias [47].…”

“…O tempo de execução remanescente pode ser deduzido a partir da capacidade remanescente de duas formas [47], se o consumo da carga for expresso em corrente, a capacidade remanescente em mAh é dividida pela corrente fornecida em mA, se o consumo de carga for expresso em potência, a capacidade remanescente em mWh, expressa energia, nesse caso divide-se pela potência fornecida em mW.…”