Bests & Worsts Reviews from Amazon

I am giving this a one-star rating because you are here looking for issues with this inverter. First, the reviews that say they cannot get 500w are very misleading. If plugged into a cigarette lighter rated at 15 amps, at 12volts that would be 180watts maximum (volts x amps). If anyone knows a way to turn 180 watts into 500 watts please send me a message because we have found the product of a lifetime. This inverter converts energy (at about a 10% cost), but doesn't make it. Hooked up directly to a heavy enough 12v source, using heavy enough cables such as provided with the clips, 500 watts is no problem. Those who complain that the unit shut off on them, that is a safety design feature. It is not that you have exceeded 500watt, but that you have exceeded a lower limit because of lower source power. I also saw a review that stated the on/off button doesn't work. It does shut down the inverter function but leaves some small LED lights on so you know power is available. The notes actually advise you to pull the plug when not in use. The last comment I will address is whether of not it is "pure sine wave". Because I do not have access to an oscilloscope I can only comment on my non-technical observation of some satellite receivers, tvs, and fans that hum on my modified-wave inverter but do not with this unit. As far as plugging in your ac to dc laptop charger goes, I do not see any way this unit can "destroy" a laptop computer. The 110v power supply of my desktop computers like it. Bottom line: Put the one-star ratings to a test of reason. Even though it may not have their expectations, this product does what it is designed to do... and does it well. If longevity turns out to be an issue I'll be back.