This combination air compressor/12vdc battery back-up has been in my possession for about one month and has not only successfully pumped up two half-flat auto tires, but seems to have accepted a fairly deep charge via a 120vac extension cord after each use. (I haven't tried recharging the internal battery from an auto battery yet.) Since this doesn't represent a very long-term or comprehensive review, I can only add that the air compressor seems robust if slow; a 10psi increase in tire pressure requiring about 2 minutes. The indicator lights, utility light, and psi guage all seem well-made, and the latter shows the actual pressure while operating, unlike cheaper gauges that only stabilize after shutting off the compressor. My only other concern/comment is that the battery cable clamps are always exposed, one on each side of the unit, and it would be possible to complete the circuit inadvertently if the unit fell into a puddle or was stored haphazardly around wire, since the cable/battery disconnect switch doesn't seem to work and the cables are, therefore, always "live". I'm not sure if this is a serious health hazard, but it certainly increases the chance for a destructive short-circuit and I'd recommend checking the function of your disconnect switch before leaving the unit exposed around children.