I hope you know Im kidding about using the solar panel as a blanket.... but they do make compact roll up panels that will charge phantom battery as fast as wall plug .... I have one of these in my garage roof and its a beast 136W x 24V you can cut it in half to 9 feet long and still be perfect for a car charger at 136W 12V....
Uni-Solar PVL-136 Watt PowerBond Flexible 24V Amorphous Solar Panel MC3
lol I know you said it in a joke. Thank you for the good information. I will review it.