BESTEK 500W Pure Sine Wave Power Inverter DC 12V to 110V AC Car Plug Inverter Adapter Power Converter with 4.2A Dual USB Charging Ports and 2 AC Outlets Car Charger, ETL Listed, Grey

Took it camping to inflate a large mattress and it worked perfectly. No hesitation and the motor ran at full speed with no extra humming or noises you'd get on a modified sine wave inverter. There's a photo attached hooked up to the car battery to do this job. This load is about 190 watts, with whatever spike that happens when the motor starts up.When it first arrived, I tested it with an oscilloscope because I was skeptical of the "pure sine wave" claim on an inverter at this price point. There's two photos attached- the one that looks perfect is this inverter running an LED 110v lamp. The one that looks a little rough around the peaks/valleys is from a 4000W inverter meant to run a house off the grid (costs several thousand dollars)- but it's running an air conditioner, refrigerator, and all the other junk people plug in at home. Still, it goes to show that this little inverter makes a really nice sine wave. This is good because many types of electrical devices don't function well (or they make weird humming noises) with a poorly shaped sine wave (or a square wave like the cheaper ones make).Other tests I tried:- Charging my Macbook worked fine with normal power plug- Connected it to a 50 watt power source to see what it does under overload. When you try to draw more power than your source can supply, it resets until you turn it off and on again then it happily tries again. This is nice because if you run it from a weak battery it won't sit there trying to make 110v and failing miserably, possibly damaging whatever you're trying to run.- Used USB port to charge the Macbook as it can accept power from a normal USB source (obviously it'll charge a lot slower because there's less power available, but still it gets some juice). Worked fine.- Charged a phone from USB, worked fineI read the bad reviews before I bought this inverter. Some of the bad reviews maybe they got a defective unit, but others are almost certainly from improper use (especially the blown fuse ones). Some things to watch out for:- The cigarette lighter or power port on your car will NOT supply 500 watts, I guarantee it unless you've got an electric car or something and even then probably not. My truck has a 20 amp fuse on that circuit and the car in the photo attached has a 15 amp fuse. At 12 volts, that means they can supply 240/180 watts respectively. And that's at the point the fuse blows, not the point you can safely draw power- the car port says "125 watts max" when its fuse blows at 180. So the people mad because this inverter "doesn't work in my car" or "blew a fuse in my car" were simply trying to draw more power from the inverter than the fuse in their car would allow.- Note in the photo above that I connected directly to the battery. If I had plugged this into the 15 amp power port inside the car with the cigarette lighter adapter, it most likely would have blown the fuse.- The power adapter on my laptop says 140 watts, so even plugging that into the inverter using the car's power port *might* blow the fuse if there's a spike on startup. You REALLY need to look at what you're plugging into this thing if you're using it inside the car and see how many watts it uses- then pad that for safety and because the inverter is not 100% efficient at converting DC watts from your battery to AC watts that it outputs.- Like any electronic device, solder joints can break if you drop it so be careful with it. Treat it like a laptop or something else you don't want broken. Broken solder joints will result in intermittent failure or complete failure. Maybe keep it in the box when you're not using it.Things I haven't tried:- drawing a 500W load to see if it really is 500W. I can only verify it supplies about 200W well.- checking how much power it draws when off with no load, or on with no load. I'd like to get around to this because would be nice to know if it needs to be unplugged when not in use.

Not a long term review. Owned for a month.Ran this with a 400 watt load for a few hours. Ran it for many many hours with smaller loads. Works very well. Fan is an always on, variable speed fan. Case never got hot even when pushing 400+ watts draw.Pulls a constant 10 watts when turned on, idle, without any load. Something to consider if you're running this on a battery.For the money, hard to beat the performance and price. The USB output is an anemic 2.4A. That limits the USB to pretty basic things. Everything checks out with this and I am not disappointed in it. So far anyway.Checked the overcurrent protection. Hooked up a 600W load to it. Immediately the device cut out. Starts right up again no problem. Seems like the circuitry is fast enough to protect itself from an overload condition.

Works as designed and good quality materials but the cooling fan really needs to be on a temperature circuit so it doesn’t drain the battery.

Having done some testing with this inverter and using it off and on, it does pretty well. AC output voltage stays at reasonable levels (above 112 Volts at very high loads) and the sign wave stays smooth the entire time regardless of the load. I even hooked up a 730 watt load to it for a short period of time and the sign wave stayed clean and the voltage regulated itself to stay above 111 or so with a 12.3 Volt input. (14+ Volt input would likely yield better results). I would NOT RECOMMEND overloading this! For testing purposes it did well for a very short period of time though the fan sped up a lot. Likely it would’ve overheated at that 730 watt load, more or less that test is just to show your load can exceed that maximum capacity for a very short period of time and this will not have any issues. (Aka if you’re powering a large fan that has a startup surge of power or similar devices.)Running at rated power though and it will do fine. As with any device I wouldn’t recommend running above 80% capacity however, just as a general safety rule.I like that this product is as advertised with a pure sign wave and a very strong output voltage. (While lower than typical residential electrical levels it is still acceptable). At Lower loads it’ll hold 116-117 Volts just fine.

This the third time I purchased one of these inverters. I have 2 for my purposes, and I gave one to my daughter when she was transporting her bearded dragons long distance during the winter. They needed to be kept warm and she was able to plug in heating pads into the inverter and then into the car's 12 volt power outlet. They operate very well. I use mine for emergency / remote power use. That means they get thrown into the back of the truck and bounced around a lot and that hasn't affected them at all. I have a few 35 amp hour UPS batteries that I can put in place to where I need some power and I'll attach these inverters.There's a little bit of fan noise, but only when you start pulling a lot of power. I do suggest connecting directly to the battery with heavy duty cables if you want to pull full power. The alligator clamps, while we'll built, aren't really meant for that amount of current.

The one I had prior to this, Beeped every minute all day. I was going nuts, I bought this one, and for the price I would pay it every time! looks amazing, works amazing, price is honestly fair, and it DOESN'T BEEP, LOL.

Great quality. Works great had an output of 114v ac. Very quite when no heavy loads are on it. This will fit where the factory inverter is on f250s with very little modifications.Great purchase.