NITECORE Summit 20000 Power Bank, 20,000mAh for Low Temperature

Fantastic. Just what I need for ultra light camping and hunting above 11ooo ft elev in rocky mountain Timberline mule deer and mountain goat basins. Spent two day at 12k ft elev temps were between 6° f and 35,°f had phone service watched a movie charged phone 3 times and pumped air mattress up twice with summit 20k and still had almost full battery bank left on summit 20k

EBC Trek Trial

Haven't tried yet but confident it will work up to 6000 meters at the Mt. Everest Base Camp. Fingers crossed!

I charged it up using Nan electricaln outlet. And then used to charge my phone 3-4 times. It's a solid power bank. I haven't tried the solar charging panel yet.