EC Technology via Amazon offers its EC Technology 18,000mAh Ultra Slim Dual-Port External Battery Charger in Black for $32.99. Coupon code "EJVQU23I" cuts it to $24.99. Plus, Prime members bag free shipping. (Non-members can qualify for free shipping with orders of $35 or more; otherwise, shipping adds $7.18.) That's $45 off list and the lowest total price we could find, although we saw another color for $5 less in December. It features 2.1-amp and 1-amp USB ports, LED status light, and microUSB cable.