LumsingDirect via Amazon offers the Lumsing 15,000mAh 3-Port USB Portable Battery Pack in Black or White for $16.99. Coupon code "96NSZP7V" drops it to $11.04. Plus, Prime members net free shipping. That's the lowest price we could find by $6. It's compatible with iOS or Android devices, features three USB ports, and comes with a USB cable. Deal ends April 16.