Sunvalley Brands via Amazon offers the RavPower 12,000mAh Dual-USB Portable Battery Pack in Black or White for $21.99. Coupon code "DEALS061" cuts that to $16.99. Plus, Prime members receive free shipping. That's the lowest price we could find by $9, although we saw it for a buck less in June. It features two 2.4-amp smart charging USB ports. Deal ends September 30.