I'm running a POS Cobra 1500 Watt inverter. I have a 3000 Watt pure since was inverter, but a nut came loose inside and it fried. Need to get it repaired or replaced. Been saying that for 4 years now, tho. The Cobra works fine. About every other year I end up having to replace it, mainly because the fan isn't working, or even if it is the unit has just been too hot for too long and becomes toast. That's just what happens to inverters that are on 24/7 and have a relatively high amp draw (more than 5 amps) nearly all the time. No amount of fuses will prevent that. The high dollar inverter tend to be designed for more strenuous applications, like running 24/7 with constant draws, tho.
I got the 3000 Watt inverter specifically for a couple of things we needed a mobile inverter for out on the farm, mainly a circular saw and a couple of other things while doing some fencing. But here in the truck 1500 Watts is plenty. The Microfridge pulls like 150 Watts, and the microwave pull 900 Watts (when the microwave is on, the fridge's compressor automatically shuts off). The computer, lights, fan, Espar heater, satellite receiver and TV along with the fridge and anything else I've got going don't come close to 1500 Watts. With everything running at once, except the microwave, the most I've pulled is 25 amps, which is 300 Watts. I've also got a 120V AC Dirt Devil vacuum which pulls 9 amps at 120Volts, which is 1080 Watts, and I've used that a time or two with several things running without any problems (the inverter squealed a few times, indicating an overload, but quickly goes silent after the vacuum gets running).
It's really hard to overload and burn out these inverters, because they have a built-in overload protection, same as the under-voltage protection where it screams when there isn't enough juice (if you wait until your inverter screams before cranking up to recharge batteries, you're just killing you batteries by discharging them too deeply, but I digress since that has nothing to do with the inverter).
Whether you get a cheap POS inverter or a really high dollar really high quality pure sine wave, the chances are it's the same cheap fans that keep them cool. A high end inverter (or laptop of desktop computer) might have an $8 cooling fan, and a cheap inverter might have a $3 fan. The primary difference in the price is fan speed, not necessarily fan quality or longevity. My 3000 Watter has two $5 fans, and I had to replace both of them after about a year.
