iMuto via Amazon offers its iMuto 20,000mAh Dual Portable Battery Pack for $29.99. Coupon code "VD63X7RB" cuts that to $17.99. With free shipping, that's $3 under our May mention and around $22 less than what most eBay vendors are charging. It features an LED display and 2.1-amp & 1-amp USB ports.