Evaluation of Charging Strategies for Valve Regulated Lead-Acid Battery

Sandhya Lavety,Ritesh Kumar Keshri,Madhuri A Chaudhari

doi:10.1109/access.2020.3022235

Sandhya Lavety, Ritesh Kumar Keshri + Show 1 more

Open Access

https://doi.org/10.1109/access.2020.3022235

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Journal: IEEE Access	Publication Date: Jan 1, 2020
Citations: 20	License type: CC BY 4.0

Affiliation: Visvesvaraya National Institute of Technology

Abstract

The present paper considers the evaluation of temperature regulated and unregulated charging strategies to select the appropriate one to ensure extended battery life with reduced charging time. Temperature regulated pulse charging (TRPC) and temperature regulated reflex charging (TRRC) are compared with the Constant current-constant voltage (CC-CV) charging strategy. In the case of CC-CV charging temperature of the battery rises with the magnitude of the current being injected and cannot be regulated without any external cooling arrangement. Impact on the State of health (SOH) and the expected lifespan of the battery are considered as the parameters of evaluation. Temperature regulated strategies are implemented through a discrete electro-thermal model, which acts as a temperature estimator. The co-efficient of the estimators corresponds to the battery parameters such as internal resistance and thermal time constants, entropy, etc. Temperature regulation is ensured in the three identified sections of charge deposited vs magnitude of the injected current. Three sections are identified as sections where the injected current is not sufficient to raise the battery temperature to set limit or not and the level of charge submitted as compared to normal charging. Experimentation is carried with 12 V, 26 Ah Valve regulated lead-acid battery to justify that increase in temperature reference of regulation allows submission of higher charge for the same charging rate. It is demonstrated that TRPC results in a significant reduction (≈60%) in charging time as compared to CC-CV and TRRC. For the same charging time as achieved with TRPC, TRPC results in almost double the expected life of operation and better SOH as compared to CC-CV and TRRC.

Highlights

Electric vehicles (EVs) and plug-in electric vehicles are in high demand due to zero contribution to air pollution
The electro-thermal and aging model serves as a temperature estimator during the charging process and plays an important part in an effective battery charging strategy. By considering all these important factors the present paper proposes the temperature regulated pulse charging (TRPC) and temperature regulated reflex charging (TRRC) strategies
The operation of the temperature regulated pulse and reflex charging is divided into three sections 1, 2, and 3 based on the charging strategy and temperature reference

Summary

Introduction

Electric vehicles (EVs) and plug-in electric vehicles are in high demand due to zero contribution to air pollution. There are some constraints such as, requirement of Battery Management System (BMS), issue of overcharging, and regulation to full charging to keep per-cell voltage stress to a lower level [1], [2]. Regulated Lead Acid (VRLA) battery is common for mass population due to its advantages over the constraints with Li-ion batteries. Longer charging time is a major concern in the adaption of EVs. Longer charging time is a major concern in the adaption of EVs This issue can be addressed through the concept of battery swapping or the fast charging of the batteries to reduce the charging wait time. Battery swapping requires a large infrastructural cost. If the battery capacity is 100Ah, charging at 10A charging is normal and any injection more than this can be considered as faster charging.

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