Sunvalley Brands via Amazon offers the RAVPower 20,100mAh Metal Unibody Portable Battery Pack in Silver for $39.99. Coupon code "DEAPB062" cuts that to $29.99. With free shipping, that's $2 under last month's mention and $20 less than the best deal we could find for any RAVPower 20,100mAh battery pack elsewhere. Designed by Studio F. A. Porsche, it features two 2.4-amp iSmart 2.0 USB charging ports, a seamless 1-piece metal shell, and multi-level protection. Deal ends November 15.