Why not get the Anker ones. Long lasting, superior quality and accurate power output and input. What is your output power requirement?
No will not recommend Anker Powerbank for the price they charge atleast.
I have 3 Anker Power Banks and 2 already have issue and they were really expensive.
the 3000mah one ( pencil shaped) the button get stuck inside.
the 10000mah one has bulged . Works though.
All of them have seen much less usage compared to my mi and still my Mi power bank works fine .
Anker is just well designed feel to it but it longevity is questionable. Even on Amazon USA many reviews are negative also.
I would recommend OT to buy 2 20000mah powerbanks instead of going for one 40000-50000. They are too bulky and heavy to carry around . Carrying 2 powerbanks of 20000mah will weigh almost same.
Plus incase one fails in emergency or gets lost in transit you will have second one in your bag.
BTW incase carrying on Plane you can only carry one powerbank upto 27000mah or total capacity of all powerbanks to 27000mah ( If I am correct)
@OP if you travel to places where electricity can be issue and charging these powerbanks might be an issue too. You can consider buy a Small Solar Panel too. they are slow in charging but a good quality one is not expensive these days.
I imported 2 from USA. One got damaged due to weight on top of it. Other works fine. 13W was the first one and it was pretty decent too.
Incase you dont want to spent much there are some really small cheap chinese ones available with 6W capacity and all. My friend use to use it for quite some time during camping and results were very impressive during good sun. Only issue is you have to be careful to keep the phone or whatever you charging away from direct sun or atleast cover them.
I burnt one of my devices due to this .