Newegg offers the RAVPower Dynamo-On-the-Go 7,800mAh External Battery Pack, model no. RP-PB09, for $21.99. Coupon code "SD224TWENTY" cuts it to $17.59. With free shipping, that's $4 under our October mention and the lowest total price we've seen. (It's a current price low by $18.) It features a power level indicator, dual USB ports, a wall charger, and carrying bag.