Right now Amazon is offering a Baseus 10,000mAh USB Type-C power bank with USB Power Delivery for only $12.99 after you clip a 35% off coupon on the product page. You'd be hard pressed to find a cheaper 10K capacity power bank that's equipped with multiple USB ports and Power Delivery.
Baseus 10,000mAh USB Type-C Power Bank for $12.99
The 10,000mAH power bank is, I think, the perfect compromise between battery capacity and size. This Baseus model measures about 6" long and 2.7" wide, about the same size as an iPhone 14 Pro. It will charge a Nintendo Switch over two times, an iPhone 15 Pro over three times, and a full-sized iPad Pro 12.9" almost one full time. That should give you several hours, if not days, of extra juice.
There are three ports. The USB Type-C port is both output and input, which means you can charge the power bank OR charge your devices from that same port. The USB Type-A port is output only and the Micro USB port is input only. The USB Type-C port supports Power Delivery with up to 20W of power. That's enough to fully max out the charging speed on a Nintendo Switch.
The Baseus power bank is UL certified and comes with built-in safety protections you'd expect from a decent quality power bank. It also has an LED battery indicator that you can check with a press of a button. Baseus itself isn't as well known as some of the other Amazon brands, but it's making a name for itself as a seller of reliable power banks and chargers.
