SFLFP123 batteries are rechargeable and reusable, saving you hundreds over 123A lithium primary batteries SFLFP123 batteries are better for the environment because they contain no hazardous heavy metals Smart, internal circuitry automatically terminates charge cycle when cells are at full capacity Safety design features provide protection from overcharge, short-circuit, and reverse polarity Note: LFP rechargeable batteries have significantly less run time than their disposable counterparts