Looking at the charging preferences of the Steam Deck, which from my research wants 45W at 15v/3A, it looks like the larger model should work just fine. And with it being $15 USD / $18 CAD this could be an incredible bargain.
It’s so new though I can’t find any info on it being used with a Steam Deck. I’ll definitely be grabbing one to try, as it would be perfect for my USB hub that sits by the TV.
The deck uses standard USB PD protocols to request power, so yes, these should work.
Worth noting, the Deck used to be unable to charge using PD chargers that were rated at less than 40W, this has been fixed in a firmware update and it is now able to correctly request power from any USB PD charger.
To charge while playing, a PD charger with a 15V mode is required, but any PD charger that can do 5 or 9 volts can still charge the Deck while idle/sleeping.
There is no limit to when it will charge, you can use a lower power charger to extend your runtime - I use my 9V 2A (18W) Pixel 4a charger all the time while playing. Anything higher than 25w will keep you playing indefinitely, as that’s pretty much the limit for what the deck can draw - 15W TDP and 10W for the screen, but obviously if you draw more than your charger can output eventually you will run out of battery.
But for quite a few lighter titles, 18W still gives you a few watts of net positive.
The only limitation that I ever saw was - if you’re using a USB-C to USB-A cable to connect to your charger, the deck will say “charging slowly” while pulling absolutely nothing. It will only pull USB-C PD power. If you have a huge battery bank that can put out tons of 9v power on a quickcharge A socket, too bad.
USB-A, per the specification, is only supposed to provide 5V max. Qualcomm Quickcharge violates the USB-A specification, so only other devices that are designed to violate the specification and thus be compatible with QC will charge faster.