Keep a charged-up Energen Power Jumper P12 Portable Jump Starter & Power Pack in your car and you'll have all the power you need to jump-start a dead battery or charge your favorite USB devices. This 18,000mAh power pack can be fully charged in 5 hours and packs enough current to jump-start a 6L gas or 3.5L diesel engine 40 times. There's also a built-in LED flashlight so you can see your battery's terminal posts to attach the jumper clamps, and it has strobe and SOS settings in case you need to signal for help. Built-in safeguards include 'smart' jumper clamps with no-spark reverse connection protection, along with overcharge, over-current, over-voltage, over-discharge, and short-circuit protection.