Bought this in May 2012.I usually carry jumper cables in my car, but not anymore. Jumper cables: you should get a set longer than your vehicle, so you don't have to back it out of a parking spot first. Then with the longer cables, you should get the heaviest gauge wire you can or you lose power through the cables. Then of course you'll need someone with a car or truck to help you!!Solution: Booster PacI really like this battery pack compared to others.1) no unnecessary gadgets like a flashlight, air compressor or 110V AC inverter. While these are handy to have they usually are of poor quality when combined in a package like this.2) Size is great and easier to carry. While all these jumper battery packs are heavy, this one is relatively narrow in width making it easier to carry at your side with arm extended.3) Takes up little room in your trunk and can be locked up with a bicycle cable lock.4) Can be charged by your auto's 12V adapter. You have to monitor the battery's green "Charge complete" LED  because there is no automatic shutoff when the charged through the 12V outlet. This means you can overcharge it and reduce it's life and capacity.5) Use it as a power source to recharge your phone or iPad etc.Maintenance notes:Be careful using this as a power supply. The BATTERY is designed to deliver peak power to start your car. It is not designed to deliver continuous power like a car battery or battery back up.For longest battery life recharge as soon as possible after each use and at least once a month.Avoid discharging it to 50% or less as this will eventually decrease power output. Recharge as soon as possible after each use to extend it's useful lifeCons:Only 1: I don't like the AC charger. The brick gets hot and stays hot even when the charge is complete. Must be an old style transformer electric vampire.CHARGING OPTION:I recently bought a modern battery charger/maintainer for the car to top off my car battery and maintain the charge when the car sits. These chargers are not expensive for the lower current models.(about $20 on up)Schumacher SEM-1562A 1.5 Amp Speed Charge MaintainerModern chargers are designed to gently charge your battery especially from 80% to full. This charge method will extend the life of your battery and give you maximum amps when you need it. When your battery is full, they go into a Float/monitor mode.I used my new battery charger on this Booster Pac and had great results. I tested the battery Pac with a professional 100Amp battery and alternator tester. The Booster Pac tested  well within the good range which was better than charge with the supplied AC adapter.NOTE: you can use a motorcycle/car battery charger through the Booster Pac jump cables or 12V accessory plug. Both work.Fortunately I have not needed to jump a car since I bought this unit in May 2012.Would definitely buy this again.Took off 1 star for the AC charger that gets hot during and stays hot after the battery is charged. It is a potential fire hazard and wastes energy.