1.1 These requirements cover primary (nonrechargeable) and secondary (rechargeable) lithium batteries for use as power sources in products. These batteries contain metallic lithium, or a lithium alloy, or a lithium ion, and may consist of a single electrochemical cell or two or more cells connected in series, parallel, or both, that convert chemical energy into electrical energy by an irreversible or reversible chemical reaction. 1.2 These requirements cover lithium batteries intended for use in technician-replaceable or user-replaceable applications. 1.3 These requirements are intended to reduce the risk of fire or explosion when lithium batteries are used in a product. The final acceptability of these batteries is dependent on their use in a complete product that complies with the requirements applicable to such product. 1.4 These requirements are also intended to reduce the risk of injury to persons due to fire or explosion when user-replaceable lithium batteries are removed from a product and discarded. 1.5 These requirements cover technician-replaceable lithium batteries that contain 5.0 g (0.18 ounce) or less of metallic lithium. A battery containing more than 5.0 g of lithium is judged on the basis of compliance with the requirements in this standard, insofar as they are applicable, and further examination and test to determine whether the battery is acceptable for its intended uses. 1.6 These requirements cover user-replaceable lithium batteries that contain 4.0 g (0.13 ounce) or less of metallic lithium with not more than 1.0 g (0.04 ounce) of metallic lithium in each electrochemical cell. A battery containing more than 4.0 g or a cell containing more than 1.0 g lithium may require further examination and test to determine whether the cells or batteries are acceptable for their intended uses. 1.7 These requirements do not cover the toxicity risk that may result from the ingestion of a lithium battery or its contents, nor the risk of injury to persons that may occur if a battery is cut open to provide access to the metallic lithium.