Bestek via Amazon offers its Bestek 600-amp Jump Starter / Portable Battery Pack in Black or Green, model no. BTCS211, for $49.99. Coupon code "8CAZ6TK7" cuts the price to $39.99. With free shipping, that's $50 off and the best deal we could find. It features a rechargeable 10,000mAh battery, car jumper clamps, two USB ports, and LED flashlight.