scispace - formally typeset
Search or ask a question
Topic

State of charge

About: State of charge is a research topic. Over the lifetime, 12013 publications have been published within this topic receiving 201419 citations. The topic is also known as: SoC & SOC.


Papers
More filters
Journal ArticleDOI
TL;DR: In this article, the authors show that traditional methods of estimating battery cell total capacity, which consider noises only in the accumulated ampere hour measurement, are biased and derive an approximate weighted total least squares algorithm that is suitable for implementation in an embedded battery management system.

178 citations

Journal ArticleDOI
TL;DR: In this article, a 7.2V, 1.25 Ah sealed lithium-ion rechargeable battery has been studied for estimating its state-of-charge (SOC) by AC impedance.
Abstract: A 7.2V, 1.25 Ah sealed lithium-ion rechargeable battery has been studied for estimating its state-of-charge (SOC) by AC impedance. The dispersion of impedance data over the frequency range between 100 kHz and 25 mHz comprises an inductive part and two capacitive parts. As the inductive behaviour of the battery is attributed to the porous nature of the electrodes, only the capacitive components have been examined. The data obtained at several SOC values of the battery have been analyzed by a non-linear least-squares fitting procedure. The presence of two depressed semicircles in the capacitive region of the Nyquist plots necessitated the use of an electrical equivalent circuit containing constant phase elements instead of capacitances. The impedance parameters corresponding to the low-frequency semicircle have been found useful for predicting the SOC of the battery, mainly because the magnitude of these parameters and their variations are more significant than those of the high-frequency semicircle. The frequency maximum (f(max)) of the semicircle, the resistive component (Z') corresponding to f(max), the phase angle (phi) in the 5.0 Hz-0.1 Hz frequency range, the equivalent series resistance (R-s) and the equivalent series capacitance (C-s) have been identified as suitable parameters for predicting the SOC values of the lithium-ion battery.

177 citations

Journal ArticleDOI
TL;DR: A new, online, battery state-of-charge estimation and monitoring system for both the discharge and charge periods of sealed lead-acid batteries, commonly used in telecommunication power systems as backup power supplies is presented.
Abstract: This paper presents a new, online, battery state-of-charge estimation and monitoring system for both the discharge and charge periods of sealed lead-acid batteries, commonly used in telecommunication power systems as backup power supplies. The proposed monitoring system is based on discharge time versus discharge rate data given in manufacturers' data sheets, and coulometric measurements, without the need for any battery voltage measurement under open-circuit conditions. The corresponding battery management system can perform both the online monitoring and battery charging tasks by the use of the same low-cost 8-bit microcontroller. Battery state-of-charge monitoring tests have been carried out under both constant and dynamic load conditions and for alternate charge-discharge cycles of lead-acid batteries of different capacities, and for different operating temperatures. The test results have shown that a very good accuracy (better than 3%-4%) in the estimation of available capacity is obtained for various charge-discharge strategies corresponding to practical operating conditions. Changes in battery characteristics which occur due to aging are also taken into account by estimating the actual capacity of the battery and adopting the corresponding recharacterization of the aged cells automatically.

177 citations

Journal ArticleDOI
TL;DR: In this article, a cost-optimal autonomous hybrid renewable energy system is developed and comparatively analyzed, considering the saturation level of each involved renewable energy source based on various technical and economic key indicators.

177 citations

Journal ArticleDOI
TL;DR: In this article, the Extended Kalman Filter (EKF) was adopted as the estimation algorithm for Li-ion batteries under varying loading conditions, temperatures and aging levels, and the robustness of the estimator against varying loading profiles and temperatures was evaluated and compared against the Coulomb counting method.

177 citations


Network Information
Related Topics (5)
Battery (electricity)
169.5K papers, 1.9M citations
74% related
Electrode
226K papers, 2.3M citations
70% related
Electric power system
133K papers, 1.7M citations
69% related
Voltage
296.3K papers, 1.7M citations
69% related
Renewable energy
87.6K papers, 1.6M citations
68% related
Performance
Metrics
No. of papers in the topic in previous years
YearPapers
2023692
20221,326
2021926
20201,245
20191,285
20181,147