I too like Goal Zero, there’s a GZ Yeti 400 sitting under the desk as I type (closer than my LM Skeletool ). But the Yeti isn’t particularly hiking friendly, so for that there is an Anker PowerCore 20100 Portable Charger, which IIRC has multiple 18650 Li-Ion batteries inside with circuitry to allow multiple USB outputs. Anker makes similar smaller units and if I was doing it again, I’d probably get a smaller single USB unit, but this one works.