AnkerDirect through Amazon has the PowerCore 5000mAh Ultra-Compact USB Power Bank in black, model no. AK-A1109011, for $12.99 (17.99 – 5 coupon) for a limited time. To get the discount, use the coupon code: Y18A1109 at checkout. Shipping is Free for Prime Members or pad your order to $25 or more and score Free Super Saver Shipping.
The Anker PowerCore 5000 features an ultra-compact tubular design (10 x 3cm) that slides easily next to your phone in any pocket or bag, PowerIQ technology to provide the fastest possible charge to any phone or tablet (up to 2A), and enough capacity to charge some iPhones up to two times.