Energizer 9000mah Lithium-polymer Car Jump Starter for sale online | eBay
FYI, you really can jumpstart your car with a 3s LiPo. This happened to me just now. : r/Multicopter
DOOK 12V 28000Mah Car Jump Starter Booster, with 4 USB 800A Portable Power Bank Battery Charger, with LED Flashlight Safety Hammer, for Car : Amazon.co.uk: Automotive