Newegg offers the RAVPower Dynamo-On-the-Go 10,000mAh External Battery Pack in Black, model no. RP-PB04, for $19.99 with free shipping. That's $6 under our September mention and the lowest total price we've seen. It features an LED status bar, dual outputs to charge two devices at once, and four connectors compatible with iPhone and iPad, as well as HTC, Samsung, and other smartphones. Deal ends December 15.