BESTEK 300Watt Pure Sine Wave Power Inverter Car Adapter DC 12V to AC 110V with 4.2A Dual Smart USB PortsClimatePartner certified

This is my first time trying this pure sine wave inverter, it works fantastic, clean, quiet 120 volt a/c current.

First: A big thanks to all of the Amazon Reviewers leaving detailed and technical reviews of this product!I've been considering an inverter for use on long road trips for years now. This spring, I purchased a car equipped with wi-fi. This kicked my consideration into serious shopping mode. I wanted to use my work laptop to accomplish things from the passenger seat. I looked at Dell's online shop and what they had that was compatible with the laptop. I then came to Amazon for the reviews of that model. Not great.Reviewers were mentioning that you need a Sine Wave inverter for laptops. Based on that information, I switched my amazon search to include that term and I stumbled upon this device. I purchased this inverter based on the thoughtful and detailed reviews from purchasers who know more about the technology than I ever will. It performed beautifully and did not even get warm to the touch.I used my laptop twice over our 6.5 hour journey. Once for approximately 3 hours while I took mandatory training though work's learning center. The second time was to respond to emails and fix a few documents and took about an hour.The USB ports ended up being a much needed benefit to this device. This was our first road trip in the new car and my husband (while setting up & testing the inverter) discovered all of the car's charging ports are USB-C (aside from the one cigarette lighter plug in the behind the center console). The car does have a magnetic charger but his phone case does not have a compatible case. We have since ordered USB-C to USB-C charging cables.Over the course of the 2 way trip, we used this device to power 1 Dell Latitude 5420, an iPhone 12 Pro Max, and 1 Kindle Fire. I'm very happy with the performance and thrilled I can work from the passenger seat instead of burning a day of PTO while watching cornfields go by.

I am so happy I purchased this inverter. My husband had another one and my laptop wouldn't work with it. I need it for when I'm teleworking as he's driving. The inverter works well with MSI Cyborg 15 A12V gaming laptop. I was able to use my wireless hotspot and play some Steam games with mixed results while riding (I almost wrote "driving" but I was never driving while using my laptop with this inverter). This was able to plug into my husband's truck and my car, and I assume would work in pretty much any car. It has a fan which makes a slight noise, but not any more than normal road noise while traveling in a vehicle. I hardly noticed the fan. What I did notice that I was playing some pretty intense games and I found that I never really went down in power which was impressive to me. I have a game pad, wireless mouse, USB hub type thing with a few more USBs and sometimes a second monitor attached and this brick takes care of power for me just like I'm sitting on my couch.

Most inverters output "modified sine wave", which is essentially a stepped square wave approximation of a sine wave. This is perfectly satisfactory for many purposes, like lighting, electronics that use switching power supplies (laptops, phone chargers, etc.), but may cause problems for devices that are quite sensitive to the quality of power they get such as motors, some medical devices, etc. Such devices need a "pure sine wave" inverter, which delivers a smoothly-varying sine wave much like that provided by the electric utility.This inverter is just such a "pure sine wave" model, and outputs a rather nice sine wave (see attached photos). It's a pretty typical sinusoidal wave with a frequency of 59.5 Hz (utility power in North America is 60 Hz, and 59.5 Hz is perfectly acceptable). The peak-to-peak voltage of my unit was 158 V, which corresponds to an RMS voltage of 111 V. This is within the nominal range of 110-120V found in North America, and should be universally compatible with any device.If one zooms in on the waveform, one can see the 24.3 kHz switching steps of about 10 V that the device produces. This is an unavoidable consequence of converting DC to AC, and it's at such a high frequency that it should have no effect whatsoever on any device connected to it. Ideally, I'd like to see some sort of low-pass filter applied to the output of the inverter to filter that 24.3 kHz noise, but then I remembered that this is a $40 item and that such noise isn't going to affect anything.The 12V cord is thick and looks to be the 11 AWG (4mm^2) cable Bestek uses for their battery clamps-to-lighter-socket set. This is perfectly fine for this power level. The 12V plug is spring-loaded and fits snugly into the receptacle.A small fan comes on as needed and isn't terribly loud. Still, it comes on periodically when the unit is idle with no load attached, for which I'm deducting one star from "noise level".The quality of the circuit board on my unit looked fine, with no assembly problems, bad solder joints, etc.There's two small downsides that I've noticed:1. The fuses are inside the unit, require its disassembly (pop off the rubber feet, unscrew the four screws there, then unscrew the circuit board inside from the supporting posts), and the fuses (two 25A automotive "Mini" size fuses wired in parallel) are soldered to the board. Again, I realized it's built to a price point, but having the fuses soldered to the board rather than being in sockets and preferably accessible from the outside of the unit is incredibly inconvenient. Having an in-line fuse in the cord or 12V lighter plug would be fine as well, but having them be internal and soldered down is annoying.2. The cord is not detachable. While Bestek offers a nice battery clamps-to-lighter-socket set, it sure would be handy to simply be able to unplug the lighter cord and replace it with a cord with battery clamps that's connected directly to the unit. It'd also make the unit more compact for storage.In short, my initial impression is that the inverter is a perfectly serviceable pure sine wave inverter that is far superior to modified sine wave inverters at only a slight price premium. While it's bulkier than some other inverters for its power level, it's not excessively large. The power it outputs is quite acceptable and makes my home UPSs (which are normally very sensitive to power quality) happy. The lack of easily-replaceable fuses is annoying enough to warrant the deduction of a star; it wouldn't be hard for them to have a higher-rated internal fuse that's there to prevent fires in the event of a major fault and a fuse for the rated current in-line with the cable or in the plug to prevent overheating in the event of a normal overload. Other than the fuse issue, I'm perfectly happy with the unit so far.