Bests & Worsts Reviews from Amazon

I bought this product at Sam's Club, but am reviewing it here so others might be more informed than I was. I run a small mobile mechanic business and for years I relied on the cheap 39.99 Harbor Freight Tools jump starter. There were several things I didn't like about its design so when it began to wear out (after about 5 years of regular use) I decided to "upgrade" to one of these Fatmaxs. After only 3-5 months of use, it has already begun to lose charge too quickly when on the shelf. Whereas the cheap Harbor Freight Jumper would drop to about 50% charge after sitting for 1-2 months (after 5 years of use), the Fatmax now drops to about 50% charge after sitting for 3-5 days (after 3 months of use); it's a dramatic drop in performance. There is another unexpected design issue with the Jump starter: it will not deliver power to the terminals unless it detects a battery connected to it. This safety feature might not seem like an issue at first, but it has led to the following: when I've had a really dead, dead-as-a-door-nail battery, it doesn't seem to detect that the battery is even connected, so it refuses to enegize (jump start the engine). Effectively what you have in this situation is a jump starter that will only do its job if the car's battery has at least some juice left in it. A second issue with this safety design comes into play when one intends to use the starter as a power source. For example, to test a starter in the field prior to install. Normally, in order to energize a starter one would connect one lead to the positive terminal and the other to the body of the starter, but this jump starter will not function that way; remember it only energizes the termnals if it's able to detect the presence of a battery. Since a starter does not posess the base charge of a battery, it will simply do nothing. Additionally, when the key must be turned several times in order to get a difficult vehicle started, the displayed power level remaining in the jump starter will drop precipitously. In some cases, the jump starter dropped to about 50% after only 3, 3-second, turns of the key to start the engine. Then, after 1-2 more turns of equal length, it often displays the remaining power as 0% or empty; 0 out of 4 bars of energy. The lights in front- although bright- are nearly useless when using them to jump start a vehicle. Reason being, they point directly at your face and not at all at the lower area where batteries are located. You, literally, have to try to reflect the light off your hand toward where the battery terminals are in order to get any kind of use out of it. Personally I never use them because I got far more blinded than assisted by them. In conclusion, the product simply fails to perform as expected. It has nice peripheral features like an air pump, usb charge ports and lights, but the rapid energy losses render it unreliable in a big way. In hindsight I certainly would not have made this purchase, and I would not recommend this product to others. Others have had similar experiences to mine, if you'd like to read their reviews you can find them on Stanley's website.