PGSONIC is a long-standing brand that offers powerful and durable lithium batteries to customers from global market. Your devices will have high performance when powered by our high-capacity product. In this product, every battery has individual cell for safety, easy storage and long shelf life. Please follow instructions on the back of the package to properly use and store batteries. Under good storage conditions, our batteries hold 100% power for 5 years. A ‘Best If Used By' Date is determined to be 5 years after manufacture and is specified on the back of the package. Feel free to ask questions about and ask for product support. We welcome your valuable feedbacks and reviews!