I'd take the piss, but I've just bought a £140 power bank with a capacity of 24a (yes, 24000mah) that can charge and discharge at 140w.
I don't even have a charger capable of that, so it's currently charging at a measly 85w from my laptop charger (which
@DeskJockey is the same one you have for your T480S - didn't know it went that high).
Main use case is for when I eventually get back into going out to see people far away, it's one less power adapter to pack, specifically thinking about the laptop but seeing as near everything I use is USB-C now and it has huge capacity it should see me for a long weekend sleeping on someone elses couch.
It also has a trickle charge mode for things that don't draw enough current to keep most power banks going (IE smartwatch). Which is nice.
This, if anyone is interested in something that's actually useful and doesn't have an equivelant that costs £15
