Goal Zero Portable Power Packs for small and large uses. The Yeti power packs are excellent sources of power in emergencies, for camping, field work or anywhere you want power with you for charging phones, running lights and other small to large electronics. The Sherpa battery packs are excellent for taking with you on the go to keep your phone charged, laptop or tablet running, and running other small appliances and lights. Pair any of these together with a Goal Zero solar panel or PowerFilm solar charger and you can always have power.