Hello, I have a [Silva headtorch](https://silvasweden.uk/collections/running/products/trail-runner-free-2-ultra) with [external battery](https://silvasweden.uk/collections/headlamp-batteries/products/trail-runner-battery-4-0ah) that uses as DC Jack to connect to the headtorch, I think it’s 3.7V.
Would there be any issues (I.e. damage, overheating) with using a cable like [this](https://amzn.eu/d/00g19YJ9) to use a normal usb battery pack or would the headtorch only draw 3.7V instead of 5V from USB.
Thanks
by toaster32
