Its been freezing cold recently so I wanted to have a go at making my own heated shirt. I had Build or Buy in mind so when I saw heated jackets and tops that cost a fortune I did some research. I found a USB heating pad for £8 on Amazon so I had to give it a try.
The heating pad is about 30cm x 30cm square. There are other sizes available though. It is powered via USB. I opted to use a large battery bank. Of course smaller ones work too. I'm sure any 5V power source could be used.
The shirt for me is an old tatty long sleeve shirt. I'm not a sewer I don't know how to make it look good so please keep that in mind. I don't care what this looks like in the end. I'll wear it in my workshop and outside. Its not for a fashion catwalk.
The idea is to add Velcro to the shirt and heating pad so it can be easily attached and removed. I cut 2 strips of Velcro, one for the top of the panel and one for the bottom. I turned the shirt inside out. Attaching the fluffy side of the Velcro to the shirt should cut down on irritation if I wanted to wear it without the heating pad. Pins work great to hold them in place.
I literally only know the basics of sewing so for me it was a case of sewing around all 4 edges of each strip to secure them in place. The sewing machine made quick work of this but of course it can be done by hand too.
The fluffy side of the Velcro is attached to the shirt and the hook part of the Velcro is attached the heating pad. Try to avoid sewing through the wires of course.
All that is left to do now is stick the panel to the shirt and turn it right side out again. As you can see in the image the stitching is noticeable but I don't think it turned out as bad as I expected it to. Its quite neat. Of course plugging the pad into a USB battery means it can just go in your pocket or a tool belt or back pack even.
I hope you found this useful. For less than £10 it gives off some great heat. The amazon listing says it reaches between 35-50 degrees C which is nice and toasty.