Thanks to Deal Hunter Navy-Wife for finding this deal.

Features:

• The 10w monocrystalline solar panel uses trickle charging to charge the battery without causing overcharging. Built-in blocking diode prevents reverse charging without extra maintenance at night. Works even on cloudy days. As frosted surface, the panel doesn’t need film protection anymore.
• PCB upgrade and addition the function of reverse and overcharge protections.And you can test the open circuit voltage normally.ECO-WORTHY 10W solar battery charge your car battery more safely and efficiently.Be a good helper on your journey！
• Equipped with SAE cable, just plug the cigarette lighter into the port or connect the battery terminal posts with the alligator clip, and the connection can be completed within 3 minutes!