The discharge resistance is relatively constant at SOC above 50 %, and increases with decreased SOC at low-SOC range. It can be inferred that at high-SOC range, the importance of Joule-heat influencing factors is ranked as temperature, aging effect and SOC, while at low-SOC range, the SOC value is most crucial, followed by temperature and aging effect.
Charge resistance is smaller than discharge resistance, meaning a smaller Joule heat production in charging process. And cell degradation results in larger charge resistance growth than discharge resistance, meaning that aging effect is more crucial in Joule heat calculation during charging.
