Groupon offers the Lenmar USB Wall/Car Charger and Portable Battery for $24.99 with free shipping. That's $45 off list and the lowest total price we could find. This USB charger functions as a portable battery, wall charger, and car charger. It features white LED indicators, 1,500 mAh external battery, integrated folding AC prongs, and a DC adapter. Deal ends October 23 at 1 am ET.