Sunvalley Brands via Amazon offers the RavPower 22,000mAh Portable Battery Pack in Black or White for $39.99. Coupon code "22000NEW" cuts the price to $31.99. With free shipping, that's the lowest price we could find by $8, although we saw it for $2 less in February. It features three USB ports and is compatible with a range of devices. Deal ends October 20.