Stay Trendy offers the Veho Pebble 6,600mAh Battery Folio Case for iPad in Black, model no. VPP-003-BLK, for $20 with free shipping. That's tied with our July mention and the lowest total price we could find by $8. Designed for use with the iPad, iPad 2, and iPad Retina, it's also compatible with most mobile devices and features a magnetic closure and zippered pockets for connectors.