Sunvalleytek via Amazon offers the RavPower 36-watt 4-Port USB Travel / Wall Charger
in Black, for $15.99. Coupon code "DFH9B7G3" cuts it to $9.49
. Plus, Prime members receive free shipping
. (Non-members can spend $35 or more to qualify for free shipping; otherwise, shipping costs $6.55.) That's $2 under our April mention and the lowest total price we've seen. (It's also a current low by $7.) It features a detachable power cord.