PoweraddDirect Amazon offers the Poweradd Pilot 2GS 10,000mAh Dual USB External Battery Pack in Gold or Silver for $21.99. Coupon code "BJY7Q66C" drops it to $16.99. Prime members get free shipping. (Non-Prime members can spend $35 or more to bag free shipping; otherwise, it adds $6.48.) That's $6 below our June mention and the lowest total price we could find by $10. It features two USB ports and a microUSB port, microUSB cable, and compatibility with most smartphones and tablets.