Fenix Flashlights Li-Ion Rechargeable Battery (3,6 V) 700 mAh Fenix ARB-L16-700 16340 700mAh Rechargeable Battery Protection Circuit in the Anode to prevent short circuit; Multiple layers of protection 500 charge cycles can be expected from a properly maintained battery Fully covered wth a steel shell for impact resistance Over charge, discharge, short circuit, and over heating protection Three sets of over-head protection: Pressure relief valve protection, separate microporous protection, and PTC cathodal block protection