To start off, I bought this product from Amazon, and then replaced it with "another" unit, then replaced "another" with "another of another" unit.I was excited about all the features on this product as they fit my needs, and at a very reasonable price. I need a unit to take on camping/long distance trips, to keep in car for emergency, to pump bikes and air beds, and of course to have as spare power for laptops and charging other small devices like cell phones and smart phones. (Such a nice thought to go to a park and bring my laptop with this unit and work on a picnic table under a tree for entire afternoon!) So it's perfect but was initially hesitant after reading many reviewers having to replace / return their defective units due to battery. And this isn't just Wagan, but Duracell and other units with built-in power storage.First one came. The unit was not flat on the bottom so it wobbled. Charged around the 34 hours max.  I was most eager to see how long it can keep my laptop running. To much my disappointment, my laptop ran for 25 minutes before the first couple of beeps, and then 35 minutes before beeping (low voltage) becomes continuous and therefore unbearable. Granted it could've been my power-hungry Thinkpad W510 - the one that uses 135W transformer. However I had another inverter that basically indicates constant use of 65 watts from the laptop, so 30 or so minutes is totally unacceptable. The unit was still able to run the compressor, and can run my car vacuum cleaner with DC adapter for another 20-30 minutes continuously after inverter stop providing AC power to my laptop.I pretty much decided the unit I got has a weak battery based just on the frequency of the reviews, so I requested exchange with Amazon. Amazon sent out a second one and I returned the first without extra charge. This second unit also isn't flat on the bottom and wobbled on hard and flat surface! After equal amount of charging time as before (34 hours), I tested this replacement unit with my laptop again. This time, I got 90 minutes of power before it started to beep!  That was acceptable. Few days later I used the compressor to pump up my bike. Guess what? The compressor gauge wasn't working! It showed zero while my tire was rock hard. I was debating whether to keep it since I was afraid that the next replacement will have weak/bad battery again. At the end I just don't think it was safe to pump while blindly guessing at the pressure, or keep swapping with a pressure tester.Called Amazon again. The customer rep understood the risks with gauge not working. So she shipped me yet another one. This time, the battery is just as good as the second unit (around 90 minutes of power to my laptop), and compressor gauge worked like it should. All's good!  But then I noticed this unit also WOBBLES! What's with the engineering or with the assembly or case warping?  This third unit wobbles less than the first two so at this point I just thank God.I then tested the USB charger. It worked, but it required turning on of the inverter switch, which therefore kicks up the internal fan. That's a bit ridiculous to run the fan while charging a USB device. I bet the fan takes more power than the phone I was charging, and then the power loss with the inverter!The flash light works and it's not overly bright but acceptable depending what your situation maybe in the dark. I haven't test the jumper cable yet and didn't need to. Cross my fingers that *will* work as it should. At this point, I'm beginning to think the odds are pretty even!The funny thing is all 3 units have a little gold oval sticker saying "QC Passed". I wonder who they hired to do the quality control, or what was done before putting on the sticker? On second thought, I don't want to know...The bottom line for me is if it works, it's very useful and a great all-in-one unit with balance of features I wanted. 5 Stars for Amazon's handling, 4 Stars for my third and working unit, -5 Stars for Wagan's (outsourced?) QC department. 3 Stars overall because I have the patience, and a sense of humor to laugh at this whole process.*UPDATE* I finally got a chance to use the car jumper twice. Both on V6 engines. With positive on battery terminal and negative on chasis, it took 2 - 3 cranks. The cars started, but the engines "reluctantly" started which leads me to believe this battery is not the strongest.*UPDATE 2* Finally got a situation where a minivan had battery with low crank (AAA reported 136 cranking amps out of 600 for the battery). This Wagan, at 13V, could not start the car.  The AAA tow guy with his smaller-than-this-Wagan jump starter started with one crank. He said it needs to be at 15V to have a shot. This mean I must keep this jumpstarter battery real full and ready to go all the time. However because this product does not automatically stop charging when full, then it's becoming a jumpstarter that is only useful when the car's battery is not in a weak state. I still need to keep my AAA membership.