The Snug & Co. Blanket charges up via a power bank, then keeps you warm on its own — you don't need to stay tethered to it. It runs off any normal 5V 2A USB power bank, so if you already have one, you're all set.
If you don't, our power bank is sized specifically for it — 8+ hours on level 1, 3–4 hours on level 2, and around 2 hours on level 3. It fits in the hidden hem pocket (its weight even helps the blanket hang properly instead of riding up), and the second port lets you charge your phone at the same time.