As a electric vehicle (EV hereafter) market grows, the number of waste batteries generated is expected to increase from 275 in 2020 to about 107,000 in 2030 domestically. In addition, circular economy for batteries is drawing attention due to issues such as soaring raw material prices and strengthening competition to secure raw materials. An EV battery needs to be replaced if the remaining capacity is reduced to 80% or less of the initial capacity, and if the remaining capacity is 20% to 80%, it is mainly reused as a power source for ESS, etc. If the capacity is severely degraded or damaged, valuable metals contained in batteries are recovered and recycled. Therefore, it is time to revitalize related industries to implement circular economy for batteries, such as recycling, remanufacturing, and reuse of waste batteries for electric vehicles. In this study, the environmental effects of new and remanufactured portable power banks were evaluated using life cycle assessment (LCA) method, and economical benefits such as resource and energy saving effects of remanufactured products compared to new ones were analyzed. Most of the portable power banks used in Korea are imported from China, and thus it is time to revitalize the domestic industry that collects and remanufactures batteries discarded in Korea. Through this study, it is expected that the environmental and economical benefits of the remanufacturing of used EV batteries will quantitatively be derived, thereby promoting the growth of the battery remanufacturing market and contributing to the establishment of a circular economy system.