Power-Innovation via Amazon offers the Maxboost 4.4A/22W Dual USB Port Car Charger in White or Black for $12.99. Coupon code "CARJULY4" cuts it to $7.99. Plus, Prime members receive free shipping. (Non-members can spend $35 or more to qualify for free shipping; otherwise, it adds $5.13.) That's $12 off list and the lowest total price we could find. It features intelligent circuit design to protect against short circuiting, over-heating, over-currents, and over-charging.

Also in the market for a portable power bank? As we mentioned four days ago, this charger is also available with the Maxboost 10,000mAh Portable Power Bank for $27.98 with free shipping.