I'm also a big fan of Anker powerbanks -- between myself and my spouse, we probably have 4 or 5 of them now (used for different scenarios). They're great. They do get heavy though, so think carefully about just how big (heavy) you really need.
Being who I am, when I first bought one I went out and got the biggest, most powerful Anker powerbank that I could find: the mighty Anker PowerCore 26800. It's a beast, bringing a full 26,800mAh of juice for your toys. It can charge 3 devices at once, and charge devices repeatedly. Just what you (think you might) need for your long, multiple, globe-spanning flights with long layovers. It's even better (for her) if you have a spouse who is hungry for power, but reluctant to carry a heavy powerbank around herself. But it sure is heavy. Eventually it dawned on me that maybe I didn't need to schlepp around such a heavy piece of gear just to keep my phone and iPad charged up, and others (ahem...) in my traveling party could carry their own if they really wanted to stream videos of Korean soap operas on their phone for many hours at a time (turns out, she does, and I don't use my phone all that much when I'm away from an electrical outlet). Having learned that lesson, I have slimmed down to a different, perfectly-capable but not-quite-so-heavy model (an Anker PowerCore Slim 10K, its 10,000mAh is more than adequate for me). I bought two of them. Perhaps it's best feature is that she now has one of her own.
My advice is to get one that meets your real-world needs (just barely), not necessarily one that will let you power all of Los Angeles after the Russkies take out the power grid in a cyberstrike.
Also be aware that, surprisingly, your powerbank may draw extra scrutiny when going through airport security. In all my recent travels, the thing that hung up going through security most consistently, has been having a powerbank in my carry-on. The US TSA inspectors never care (no comment...) but the diligent security staff in European and Asian airports have all been flagging this for careful hand inspection. These days I travel with a seriously large carry-on bag chock full of electronics, multiple cameras, a bunch of charging blocks, MANY cables, scuba gear, a drone, and several mysterious-looking odd electronic devices -- probably looks like I'm on my way to a terrorist trade show. The xray belt always stops when that bag is going through the scanning box, I can see staff gathering around, pointing to the screen, switching the color scheme and changing to whatever alternate views they have, mumbling concerns... OK, I get it: my toys look unusual and worrisome.
Invariably, the bag comes out and is picked up by one of their inspectors for a closer look, as they pull me aside, I always hear them ask... "Powerbank? Please show me." When I do, they look carefully at it for the power rating (this is regulated, and limited -- I've read that Chinese airlines are particularly strict about exceeding their allowed capacity). Once they find the teeny tiny technical rating on my powerbank, they are satisfied, they hand it back to me, and they have zero interest in any of my other electronic exotica, so I can reassemble my bag and move on. Maybe it's the powerbank combined with all the other odd stuff, maybe it's just me and the vibe I give off, maybe it's my dear spouse standing next to me impatiently and rolling her eyes. But you may find having your powerbank along will add a brief stop at the xray machine and some personal attention from a polite foreign airport security agent (if so, maybe pull out your powerbank and drop it in the little plastic tub along with your phone/iPad/laptop).