These high performance 14500 lithium ion 3.7V batteries offer high performance and long life from a compact package. They are the same size as a standard AA battery. So they are compatible with our range of AA battery mounting hardware. Lithium-ion rechargeable batteries offer excellent properties for use in consumer devices, including excellent energy density and low maintenance. Lithium-ion do not suffer from memory effect and possess no regular cycling that batteries often require to extend their service life. Dimensions: 14 x 52mm Common Applications Include: Laptop computers LED flash lights Electric vehicles Power tools Converting AA or AAA powered products over to higher performance (providing voltage matches).