I'm spending my social isolation time researching my next p.c.t. section hike, and torn between "longhike" and "gadgets" sections,for this question. …….I've been using traditional compass & maps.. augmented with gps and trail guides.in all, quite a lot of weight. And starting to think that using my cellphone would lighten the pack. typically I turn on the gps, about 6 times a day, hiking. and to date I've never needed to change out a battery set on it. always turn it off when not actively being used- same plan for the proposed phone use. longest hike was 14days ( I figure that my personal limit is two weeks (+/-), before I have to get a shower and clean my hiking clothing-this gives me my "expected time away from a charging port. I'm going to retain paper maps&compass, for the time being. so how has this worked out for others? any disaster stories? issues that are not apparent? I would like to avoid taking a "out of device", battery or solar charger.