Let me introduce you to my best friend on the trail:
At 150g (5.3oz), this is the lightest 10000 mAh power bank on the market. It comes at a steep price of around 50€, but weight, durability (it’s titanium, baby) and the rather beefy 38.5Wh output make it more than worth the investment.
I carry two of those. Why two? Well, if you clicked the link, you know, else here’s the TL;DR: It is insurance against theft in hostels (one’s gone, still have one), breakage (oops, it’s in the ocean), and as a convenient and powerful way to make a fellow hiker very happy. Empty phones are the bane of most hikers’ day.
With my Apple Watch Ultra, I’ll probably use my phone much less for navigation and to stay on top of friends’ location on the Camino, but still… not being able to reserve ahead would be rather problematic this year. So, yeah, more power to me. Literally.