I came to recommend the same thing. Keep things low tech and low electricity.
You can get much cheaper options for shaving. $10 Omega Synthetic shaving brush that will hold up to travel better than a nice badger/boar brush. $12 Weishi twist to open razor that has less parts to deal with than the Merkur (twist to open versus 2 pieces that come apart). And if you're a weight weenie, get a shave soap puck that can work as a body soap too. Wash your body, then hit the brush on the puck, lather your face, and shave.
For beard trim, use some scissors. For nose/ear trim grab one of these. The DE blades are normally 15-20 cents a piece and you can normally get a few shaves out of each blade.
That should be a nice grooming kit that does not require any power and really should last you for the rest of your life if you take care of it.