Heated riding gear can't be beat in the winter, but if you ride a bike with limited alternator output, a typical electric vest can put a strain on your electrical system that could leave you with a dead battery when you need the spark the most. The Electric Warmbib from Aerostich covers just the front of your torso, and draws a mere 30 watts/2.5 amps, which should be well below the maximum juice available from even a single-cylinder dual-sport. It packs small in a built-in zippered pouch, and comes in two sizes depending on your height. Read more about it here.
(Note: I have not tested this product, nor have I received any compensation from the manufacturer for including it in a Product Spotlight. I just thought it was interesting/innovative/clever enough to warrant bringing it to your attention. All specifications and claims for the product are the manufacturer’s.)