[ip26]

You may need to charge… but the Garmin uses something like ~10mAh/day? You could top off the watch for months with a single pair of AAA batteries.

[ghaff]

Just make sure you keep them warm.

It's been a while since I've done any high-altitude mountaineering. I honest don't know what people actually use these days. Certainly GPS watches didn't exist when I was climbing. Not sure if people use power-hungry watches that need to be charged these days or not.