I have tested hundreds of portable chargers over the years, but the Anker Laptop Power Bank ($94, down from $135) is my current upgrade pick of the best power banks. It’s 30 percent off for Prime Day, and that’s the cheapest price I’ve seen for this charger. For alternative discounts, try out our Absolute Best Prime Day Deals roundup, or our Prime Day liveblog for handpicked highlights from the sale. Anker Laptop Power Bank DealThe Anker Laptop Power Bank is a versatile beast. Plug into an outlet and you can fill the Anker Laptop Power Bank from empty in just two hours.