I am looking for portable 12V battery operated water heater to control water temperature in my manual espresso coffee machine. I saw this image of something similar, but it doesn't seem to exist anywhere for purchase.
Here is a picture of the machine that I currently have.
https://www.pinkselixir.co.nz/uploads/8/2/3/5/82355672/img-0110_orig.jpg
I'm well aware of the existence of larger water heaters that use cables and the like, however, I would very much like to have something similar to the picture I attached. Here is an article of the tool in the picture. I've found very little other than this evidence of its existence, even after searching the zwilling website.
https://dornob.com/hot-water-to-go-portable-battery-powered-drink-heater/
Can anyone make any recommendations as to a similar product? More details in comments.
Thank you for any assistance!