There are, however, USB-PD sources that can run from a fixed voltage DC supply.
I would actually really like something like this that can fit in my backpack with just shy of 100Wh (airline limit) of energy storage, a retractable cable to plug into an outlet, and monitoring via USB. In theory, I could build this myself around OpenUPS, but sourcing a pack, retractable cable and suitable enclosure is really annoying.
There are, however, USB-PD sources that can run from a fixed voltage DC supply.
I would actually really like something like this that can fit in my backpack with just shy of 100Wh (airline limit) of energy storage, a retractable cable to plug into an outlet, and monitoring via USB. In theory, I could build this myself around OpenUPS, but sourcing a pack, retractable cable and suitable enclosure is really annoying.