Sunvalleytek via Amazon offers the RAVPower 36-watt 2-Port USB Car Charger in Black for $11.99. Coupon code "KINJA805" drops it to $7.99. Plus, Prime members get free shipping. That's the lowest price we could find by $6. It features iSmart 2.0 smart charging technology, dual USB ports, and multiple built-in protection methods.