Comparative evaluation of battery charging strategies: Thermal behavior and charging performance

As a core energy storage component in renewable energy systems, lithium-ion batteries face critical challenges in balancing charging performance with thermal safety. While existing studies have explored conventional charging strategies, systematic experimental comparisons under varying ambient temperatures remain limited. This study presents a comprehensive experimental investigation into the thermal-electrical coupling effects of seven advanced charging strategies, including constant current (CC), multi-stage constant current (MCC), changed multi-stage constant current (CMCC), boost charging (BC), constant power charging (CPC), positive pulse charging (PPC), and positive-negative pulse charging (PNPC), across a wide ambient temperature range (15 °C to 45 °C). The results indicated that BC demonstrated superior performance in terms of thermal uniformity and temperature fluctuation control. Compared to the other charging strategies, BC reduced the maximum temperature rise at the center of the battery surface during charging by up to 39.62 % and improved energy efficiency by as much as 3.74 %, making it particularly suitable for applications with stringent requirements on charging rate and temperature control. Moreover, it was found that the critical ambient temperature range for enhancing energy efficiency was between 25 °C and 45 °C. Additionally, the charging times of BC and CPC were highly sensitive to ambient temperature, suggesting that temperature should be carefully considered when optimizing these two charging strategies. This study provides theoretical support for tailoring charging strategies for lithium-ion batteries in various application scenarios. Moreover, it offers valuable reference for the research and optimization of fast-charging strategies.