I just bought the cheap one at HF as well (the one that is a battery pack and light, nothing else, no compressor, no USB, nothing) and it is pretty nice. I added a monthly entry to my calendar to charge it overnight as that is why they usually fail, lack of charging. I found I use it to test things I am making for my car (12v from battery charger fluctuates too much depending on load, stand alone battery can't be brought in the house, etc) as well, and have ran an inverter and an LCD and movie box for many hours.