u/Doortofreeside

I've seen the official specs that the Forerunner 970 gets around 20 hours of battery life with GPS on, but I've also seen posts stating that the real battery life is closer to 10-12 hours in those conditions.

I'm planning to do some long solo hikes (presi traverse, pemi loop) that will be up to 31 miles and take potentially 20 hours. Part of the appeal of getting this watch is having the navigation on. What i'm wondering is how do people manage the battery life in these scenarios? Do you bring a power bank to charge it on the go? The goal would be to hike continuously for up to 20 hours, and to have a margin of safety in case something went awry.