On hikes all sorts of things happen to you. Sometimes pleasant, sometimes less so, but the things we experience ourselves are worth a lot anyway. On the other hand, questions arise that we often don't know the answers to ourselves.
Of course I invite all forum members who have something interesting to say, show, advise or know the answer to the question to participate.
And here is my first practical and very useful experience that comes in very handy on hikes (especially multi-day ones).
This June, four of us (wife and a couple of friends) set off on a two-day hike from Golica to Stol. We slept in the hut on Golica and headed early in the morning towards Stol. On the wonderful hike I took lots of photos with my phone, had some talks, browsed the internet a bit and suddenly realized my mobile was dead. Annoyed and angry at myself, I turned it off and didn't use it until Prešeren hut on Stol, where at the next table I noticed a mountaineer had his phone plugged into something box-like. Curiosity wouldn't let me rest, so I went over and asked what device he had on the table. He kindly explained it was a portable battery, with which on hikes he no longer needs to constantly watch his phone's charge, nor turn it off like he used to. He advised me to get the battery online from China, where I'd pay about four times less than here. The info seemed unbelievable, as I hadn't even heard of such a battery. Of course, that same evening when we got home, I ordered a 30000 mAh battery on aliexpress site and got it four weeks later. Paid 12 euros for it. Here it'd cost 30-40 euros, and no store had one with that capacity (checked Big Bang and mimovrste). While waiting, I asked how much power one charge takes approx. Found out around 5000 mAh, so battery should do about 6 charges, which of course isn't true (you know, Chinese!). After testing, it charges the phone a bit less than four times, but that's still great. For 12 euros, wife and I basically have three full phones each (1x home and 2x in mountains), so no more worrying about our phones' energy state.
The portable battery (English Power Bank), which anyone can really afford, has become part of my mountaineering gear. It's small (my device's 14 x 6.5 x 1.5 cm) and light (180g), easy to carry. Can charge two phones at once, even while hiking in backpack. Just need cables for each.
Warmly recommend to every mountaineer.
What experiences do you others have with such batteries? Do you use them?