Profile: Tech Gadget Supplies Inc. specializes in providing batteries. 16340 battery is a li-ion cell classified by its 34mm x 16mm dimensions, and it is the latest rechargeable version of a CR123A battery. These cells usually have 3.6V or 3.7V voltages, a button-top terminal, and most use LiCoO2 chemistry. While some come with built-in USB charging ports, all 16340 cells are rechargeable in li-ion smart chargers. The 16340 cells are commonly used in flashlights or other small compact electronics. AA 14500 high capacity 800mAh 3.7V Li-Ion rechargeable battery is an ideal battery for building power packs with fewer cells needed than for NiMH or NiCd batteries.