We’re somewhat anaemic of good Powercore deals, but if you don’t own a Powercore you should!
I own two of these. I’m not so sure I’d recommend them, I got mine for quite a bit less than this cost, they are handy for when carrying on your person, if I’m with a bag I always go with the next model up the 20000mAh PD.
Worth noting if you do use the USB-C port at 20W then it drains less efficiently, you get less total energy out, so I’d recommend by all means charge if from 18W PD charger but try to use the USB-A port to get more capacity out of it.
I also if I’m out walking all day with a phone is I begin with a charged phone and keep the 10000 PD plugged in as then it’s only outputting quite a bit less than 10W and of course if you use a Powercore to keep a phone charged, you don’t waste the extra energy of charging a phone’s battery to then discharge (i.e. charging a charged phone has less power losses in the chemical processes).
So with that trick you get nearer to two phone recharges vs if you simply plugged in USB-C a phone to charge a flat phone you’re going to get nearer to one phone recharge.