hi in undecided about what battery pack for backpacking, expedition or regular hiking for various day, in my recent research i have try these battery pack that googd or not for that i see they are the best choice on the range of the 100/150 dollars.....however i d'ont chose the goal zero yety pack beacause i must take they on my shoulder.....however are they: this is the first time that i see one such it, http://chargeall.com/product/portable-power-outlet/ the rav http://www.ravpower.com/ravpower-23000mah-portable-charger-external-battery-charger.html , and the volatic http://www.voltaicsystems.com/v72 and the powergorilla https://www.powertraveller.com/en/shop/portable-chargers/professional/powergorilla/ they are the more affordable for the price and quality at all, but if you have a better good coucil about one type more good for the total Mah or the quality and price or rugged case or waterproof i luky very much, i remeber that now i have a 20 watt for the solar recharging ! good things and great forum!:ylsmoke: