I have not had a chance to use my heated vest yet, but I am looking forward to wearing it when the weather turns cold again. The concept is genius. I was unable to use the first vest I ordered because it came without a battery. I was frustrated that I ordered a heated vest that was sold without a battery. To purchase the battery separately was signficantly more expensive than returning the first vest I ordered and buying another vest with a battery. By the time that arrived, the oold weather had passed. I would recommend adjusting your advertising to make it abundantly clear that your heated vest that is sold without a battery is only for people who already own a battery (which I imagine is an extremely small population).