A case study into a battery company and their 18650 batteries

•As a case study, a battery company's reliability capability was analyzed. The company is only a shell company with no design or manufacturing abilities, and batteries under the corresponding trademarks have defects, lack sufficient protection mechanisms, and are generally at risk of being unsafe.•Recommendations for the selection of batteries are provided, including supply chain analysis, testing, and teardown characterization.•Device manufacturers should check the qualifications of potential suppliers to get quality batteries.