Gooloo via Amazon offers its Gooloo 7,500mAh Jump Starter Power Bank in Black, model no. F001, for $59.99. Coupon code "WUB3RYHL" cuts it to $39.99. Plus, Prime members bag free shipping. (Non-members can spend $49 or more to bag free shipping; otherwise, shipping adds $7.) That's $20 off and the lowest total price we could find. It can charge a car from the inside of the cab by plugging into the cigarette lighter. It also features a flashlight and two USB ports.