300Watt Pure Sine Wave Power Inverter DC 12volt to AC 120volt Car Converter Adapter with Dual USB Ports for Smartphones Laptops Tablets

I've seen Giandel inverters on Amazon for a while now. They always seem to be well received and well reviewed, but I haven't had the need to buy a new inverter until recently. I was making due with some older modified sine wave inverters and they were doing the task well enough.So this one was bought to replace one I let the smoke out of. Honestly, i was looking more for an inverter to fit within a specific cubby in my battery box. I wasn't looking for performance per se, just size. This Giandel 300w fits the cubby perfectly so points for form factor. The performance, yeah I lucked out on that.For performance, its top notch. I am happy with it as it does what I intend for it to do - power smaller loads such as my laptop / mobile office or charge my cordless tool batteries when away from the house. It does the job effortlessly. There isn't much to say. It does what it is supposed to do, and that leaves for a less than thrilling review. Would i recommend, I absolutely do.Small quirk for an honest review to be complete.... it seems like this inverter will do a full power draw when you power it on. Self test i assume. When it does this test, it goes to town I guess. When I first plugged it in to verify it worked, it blew the 15 amp fuse I had it on. Well yeah, it'll do that you say. Yes it does, under load. I was expecting it to just turn on and sit there until loaded, but it seems to pull heavy current for that apparent self test. properly rated fuse (same as the fuse in the inverter) fixes this.Just a thought to consider.

This is my third Giandel inverter purchase and I have been happy with all 3. My previous purchases were the 2200W sine wave inverter and the previous version of this 300W sine wave inverter. Since I used to design inverters and UPS systems, I was intrigued how they got the cost down for a sine wave inverter. The PWM control and output filter add significant cost over a modified sine / step wave inverter. There are not many loads that a step wave is safe to use, with motor and magnetic / transformer type loads being the worst. Also, any electronic load that has EMI filtering (computer, TV, electronic blower for HVAC, etc.) can damage the EMI filter in the load. I do not believe most people should risk using a modified sine inverter. You are getting what you pay for, and can damage some of your appliances and even cause fire.The manual specs that interested me are:Continuous 300WSurge power 400W +/- 100W (can be as low as 300W!)I measured only 506mA of current without any load. That is only about 6W at idle.When I first tested this, I found I could easily cause the under voltage alarm to trip, which is latching. You have to cycle the power switch on the unit to reset the alarm. What I found was as expected: any voltage drops when the inverter is starting or running will help cause the UV alarm. These could be: poor battery, wiring that is too small, small wiring to the cigarette lighter socket, fuse voltage drops, and poorly seated cigarette lighter plug. So if the UV alarm trips, check these first before blaming the inverter. Just like with me, it is likely to be user error.My only negative on this is that it does not have UL or ETL safety marks, which indicates that the product has been safety certified for electric shock and fire. There are a ton of products coming from Asia that are poorly made and do not have these safety marks, so when I end up with one, I check it out before using. Which I did for voltage spacing. :)They used reasonable safety spacings, and I noticed that they have good designs for EMI noise as well. The ground prongs are left open on the standard 120V outlets (NEMA 15-20), so be aware that the ground is open. This is typically fine with most appliances but consider it only truly safe for double insulated appliances. Note that this wiring trick is common on many low power inverters, but not on UL/ETL inverters or UPS systems!Overall, I found this a good buy and safe to use with my CPAP machine - with a floating battery and double insulated CPAP device.

While this may be a 300 watt inverter, the issue is that the cigarette power cord significantly limits it's useful power to about 120 watts. Assuming your car is running, and the available voltage is around 14 volts, a 300 watt inverter will pull at least 22 Amps of current (more because it's not 100% efficient).Because this inverter uses a cigarette lighter plug, what they don't tell you is that most cars/trucks only supply about 10 amps to a cigarette lighter plug. So in a typical automotive setup, if you try to draw more than about 120 watts from the inverter, you'll end up blowing the cigarette lighter plug fuse.There are other options to get more power/current from a cigarette plug. For example you could wire your own plug directly to the car battery. But even in this situation, cigarette plugs aren't designed to handle much more than 10 amps. They do not provide very secure connections, and If draw much higher current, you're likely going to melt one or both ends of the plug.In addition, the wire that comes out of the inverter, going to the plug is maybe 16 gauge wire, which is only rated for about 12 amps. Because the length is so short, you "might" be able to push it a little, but if you tried to pull 22 amps through it, to get the full 300 watts, the wire would start to get very warm and possibly melt the insulation. All around an unsafe situation.So in the end, while "technically" you have a 300 watt inverter, you'll never SAFELY be able to hook up a 300 watt load to it without melting either the wire or cigarette lighter plug.Well, why did I give it 4 stars then? Ignoring the 300 watts, it's a very well constructed inverter. I've been using it for about 2 years to power laptops, and power tool battery chargers. All loads less than about 100 watts. The inverter has worked nonstop. It doesn't get hot at all and the fan is very quiet. I've hooked it up to an oscilloscope to check the output waveform, and it is a very nice, clean (symmetrical with no discernible stepping) true sine wave. For the price, it's hard to find something this accurate, even through it's only practical to use it up to about 120 watts.