My wife purchased a GOBI heat jacket for me that came with 2 batteries and a charger. I have used the heat function a couple of times, but the jacket is light weight yet keeps me warm enough without the heat turned on. I am really surprised at the weight of this coat vs the amount of heat it retains and so far I rarely use the heat function. It has the Hi-VIS reflective stripes to be Class III compliant and can be used on the projects that I work on.
https://gobiheat.com/collections/mens/products/flash-reflective-heated-jacket?variant=7338153476147