I've been a pro auto tech for long enough now that all the normal tools have been bought and paid for. You start looking for other things that you never really wanted to spend the money on, but always irritate you when the shop you're at doesn't have one, or the one they have sucks. I bought this because the place I was at, for a short time, reconditions and resells used cars. At any point in time we would have anywhere from 2500-5000 cars at the facility. It's a huge place, and a lot of dead batteries. On a daily basis I would need to jump start 4-10 cars. Cars ranging from tiny electric cars to diesel trucks. Out of the hundreds and hundreds of cars I've needed to jump, only one of them would the Genius not jump. And this was only due to an extreme discharge (1v), and no direct access to the battery terminals. Only tiny remote jump posts were accessible. The description claims that this will jump up to 20 cars on a single charge. I can vouch that this is an under estimate. I could use this all week, jumping 30 or more cars, before charging. I only plug it in when it reaches 25% according the to the LED indicators. On a very regular basis I would need to jump electric cars. Electric cars have a regular 12V battery for starting, and the motors run off a special battery. More often than not, the 12V battery, and the motor battery would be dead. So I would use the NOCO to start the car, then leave it connected in order to drive it to the shop (up to 1/3 mile from where cars parked). This little jump box will run an entire electric car with AC on full blast for several minutes and barely deplete its charge. However doing this multiple times throughout the day will deplete it more quickly. But if all you need to do is jump start, the charge lasts forever. Obviously you can use it in a similar way on a gasoline engine to run the car, when the alternator is bad. Only a few, very minor, points to mention. The cables are a little shorter than I'd like. This makes it more compact, but sometimes finnicky to get connected to a battery. The location, and ease of activation, of the light button make it entirely too easy to turn the light on. I found many times, I accidentally turned the light on without realizing it, and it stayed on for who knows how long until I noticed. Also it's a bit heavy to carry around. And this I only say because I had to carry it around in a backpack with other tools, and things I needed to do my job. For the normal person, the weight isn't an issue. It is by far smaller, and lighter, than the traditional jump box. And lastly, it takes a long time to fully charge. The better part of the day, if mostly depleted. So that's it. Those minor points are so minor, in no way should they deter you from buying this. I absolutely love this thing, and only hate that I waited so long to buy it. Update: Been using this now for almost 2 years. Still going strong. Working in a normal shop now, so not jump starting batteries every day. The charge still lasts forever. Also use to bench test starters. I now charge it probably once a month. It never goes dead, but if I see the charge is depleted when I use it, I will throw it on the charger. Still the best jump box I've ever used. Update: I bought this in March 2017. I'm now buying a second one. I want one for home now, so I'm getting the new one for work, and taking the old one home. I'll still love this jump box. Still working on cars, still jump starting cars on the daily. Now that this box is nearing 5 years old, the battery does need charged more often. Think of your old smart phone. But it's still kicking strong. The cables are still annoyingly short. I charge this every few weeks, and use it pretty much daily. The rest of my previous review still stands strong. The only difference now, is I have to charge it more often because the battery is so old. But still perfect for home use, and now I'll have a fresh new one for work.
