AMAZON has a bunch of them. Check the ratings. The one I got has a small battery (about the size of a box of cigs. but not as thick), w/ charger, says it'll last 3-5 hours depending on setting, 3 settings. It kept me very comfortable on low, for 2+ hour ride, I turned it off after that. Mine has heat coils in the front, chest & belly area, sides, back & shoulders. In the photos, it's black w/ red circles showing the heat areas. Don't remember the brand name, it's up at my shop w/ all my other riding gear. It's after 12 midnight here & I'm not going up there. I'm afraid the boogie man might get me.
I have a Fist Gear Heated Jacket Liner and Gloves. I have had them for about 10 years. I am very pleased with the performance of both the jacket liner and the gloves. First gear has a separate heat controller which I have hard wired into the bikes electrical system. The jacket liner has full sleeves and It puts out a lot of heat. Also you can wear the liner as a windbreaker when off the bike, just put the cord in the pocket and no one can see its a heated liner. First Gear is not anywhere close to the cheapest but it is durable and it works.
Az Wingrider