I am getting a vivoactive 4 and I plan to do backpacking hiking trips with it. The only problem is the battery life with GPS is only 18 hours. Should I bring a charging bank or should I do it without GPS. My hiking trips are only 3 or 4 days long so the battery life would last the hike without GPS but should I still use GPS because I want more accurate mileage? What do you think I should do?