Use Amazon coupon code EYB5BBOJ
Amazon has this RAVPower Dynamo-On-the-Go 10,000mAh External Battery Pack for $59.99. Use the coupon code and the price drops to $39.99. The battery pack features an LED status bar, dual outputs to charge two devices at once, and connectors compatible with iPhone and iPad, as well as HTC, Samsung, and other smartphones. Shipping is free.