Hisgadget via Amazon offers the Intocircuit Power Castle 11,200mAh Dual USB External Battery Charger in Gray or Silver for $22.99. Coupon code "2TR69NY8" cuts it to $15.99. Plus, Prime members bag free shipping. (Non-members can spend $35 or more to bag free shipping; otherwise, shipping adds $5.99.) That's $2 under our mention from two weeks ago and the best price we've seen. (It's also a current low by $6.) It features a 2.1-amp USB port for charging tablets, a 1-amp USB port for charging most smartphones, LCD display, and travel pouch.