This jacket should fit snugly to keep the heating elements close to your body, rather than loosely to allow layering. The jacket runs large. I usually take a size small but this was too big for me, more like a women's medium. See measurements in photos. After just a couple of wears (jacket is like new), I decided to order an XS instead. When fully charged, the battery provides up to 10 hours of warmth at low level heat and up to 3 hours on high heat. Battery and charger are included (the "original price" in the listing includes the value of the battery,). Jacket is machine washable, wind and extremely water resistant, with a detachable hood and zippered pockets.