Coulomb counting

Ng KS, Moo C-S, Chen Y-P, Hsieh Y-C (2009) Enhanced coulomb counting method for estimating state-of-charge and state-of-health of lithium-ion batteries. Appl Energy 86 1506-1511. doi 10.1016/j. apenergy.2008.11.021... 

In order to improve SoC estimation, coulomb counting and voltage-based methods can be combined. In this method, a cumulative error of the counting integrator can be... 

Comparison between state of charge determination methods for lithium-ion batteries based on the measurement of impedance, voltage and coulomb counting... 

Criteria Method Voltage Impedance Coulomb counting... 

Coulomb counting was used as reference in the experiments presented here. Despite its initially mentioned disadvantages it is likely to remain state of the art in SoC determination. The investigations confirmed the point that the best way to counteract the drawbacks of the individual methods and thereby to achieve the best results would be to combine different methods e.g. by a fuzzy-logic approach (Schalkwijk and Scrosati 2002). It was also shown that the SoC determination has to be optimised for each type of Li-ion chemistry since they differ considerably in their characteristics. 

Many battery monitoring systems rely on voltage, current, and temperature measurements advanced devices also include coulomb counting. Sensors provide SOC information and identify irregularities, but capacity estimations are beyond reach for most battery management systems (BMSs). 

A key element in management of hthium batteries is the accurate and reliable determination of battery state-of-charge (SOC), whether or not the "history" of the battery is known from date of manufacture. Rehable SOC measurements are critical for many devices. Well-known interrogation techniques used to measure battery SOC include coulomb counting [11], voltage recovery [12], and electrochemical impedance spectroscopy (EIS) [13]. Often, these approaches yield data that is highly nonlinear, complex, or intractable, especially for rechargeable battery systems. 

Primary Li/SOa cells are important for applications such as the SINCGARS radio. We have developed two fuzzy logic-based approaches to determining the SOC of these cells - one suitable for an internal meter based on Coulomb counting and another suitable for an external meter based on ceU impedance measurements. 

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