HTS code 9902.16.20 covers "Rechargeable lithium batteries, certified by the importer as having a polymer electrolyte layer and composite cathode, designed to complete 800 cumulative battery lifetime hours and operate at sustained temperatures between 45 degrees Celsius and 130 degrees Celsius continuously for a minimum of 1 hour between recharges (provided for in subheading 8507.60.00)" under the US Harmonized Tariff Schedule. This is the official duty rate charged by US Customs when this product is imported into the United States, sourced directly from the U.S. International Trade Commission and refreshed daily.