Hi Ryan, thanks for your post, for your call earlier this week, and for your purchase!  I think we answered your questions about power supplies, but just for historical purposes, here is the link to the Amazon page where we share the models of USB power bank that we recommend for use with large kits like the Hogwarts set.

https://bit.ly/amazon-brickstuff

The important thing when shopping for a battery bank is to get one with a physical on/off switch-- most battery banks have a "soft" on/off power function that turns off the pack after a period of low power consumption.  Because all of our products use LED lights (which don't consume a lot of power on their own), we find battery banks without physical switches often power off when they shouldn't.  With a physical on/off switch, you're always certain your set is getting power.