[logfromblammo]

Couldn't you get around that with a really long USB-A-to-whatever charger cable?

Slapping a Stirling engine on a rocket stove just seems like a really good idea to me. My major concern would be the in-backpack weight and volume.

[hinkley]

DC doesn’t like long runs, but I believe there’s a battery in that yellow block along with the charge circuitry. If I’m wrong it may warrant another look.