300W Power Inverter 12V to 240V 230V Pure Sine Wave Inveter with 4.2A Dual Smart USB Ports Car Adapter for Cars, Vessels and Power Failure Emergencies (300W-Red)

I've only used it a couple of times for a few hours, but so far it works well, runs very cool to the touch (good efficiency) and is very quiet even with the fan running. It has sturdy +/- terminal posts and comes supplied with 2 solutions: cigarette socket connectors for in-car use, and croc-clip connectors for outdoor/camping leisure use, both solutions use the same ring connectors to screw onto the terminal posts securely to prevent arcing problems. If you don't need to supply more than 300W continuously then this is an excellent low cost solution that seems well engineered and provides a true pure sine wave electrical output signal that mimics household mains electricity to protect your sensitive electronic devices. Highly recommended.

I bought this to replace a non-pure-sinewave Inverter which previously damaged a laptop supply. I cautiously powered this one up from a 12V car battery and using a resistive voltage divider and non grounded portable oscilloscope I checked the output wave form and found it to be quite clean and 'sine wave like!' Unit is silent in operation. Output voltage was encouraging as it nominally read 230V AC 50Hz and corrected for increasing load. So far I have tried it with phone chargers and a small bench drill, (100W), both the wave form and voltage coped well with varying load on the drill. I am reasonably confident that while it continues to work as it did today it should be fine with my laptop. Interestingly, the unit does not need to be switched on to operate the 5V USB outputs a feature which should improve efficiency if all you need to do is charge portable devices from USB. I have yet to check the operating efficiency. For me the 300W output rating should be adequate to serve most of my requirements and to be quite honest, any greater power rating is going to discharge a car battery even more quickly. You don't get ow't for now't! I like it, its a great addition to my camper and home tool kit.

Very usefull size works okay

Very disappointed, while there is no doubt this unit functions very well "as an inverter" there is a significant problem in that the cooling fan runs all the time it is connected to a 12 volt power source. This means that beyond any ongoing power requirements by the electronics there is a further "parasitic" drain caused by the operation of the fan. This is entirely unnecessary when the unit is not under load. I am very disappointed that this will impact the "stand-by" life because of this constant battery drain.

Bought a cheap one and it was horrible, used loads of power (60% efficient) and made everything buzz. This one is great. Charges my Bluetti power pack via mains charger at 195w while only pulling 235w from the battery. Very happy with it. Spend the few £ extra and get a pure sine wave one - you won't regret it.

I bought this to give me remote power to my amplifier, mixer and keyboard when busking. Total load is only a few amps but I went for the 300w model as we could also use it in the car for long journeys via the cigar lighter cable. It's running off a 30Ah leisure battery using the robust crocodile clips and it's been great. I was worried by reviews of rival inverters being noisy due to the fan but this Bestek fan is super quiet. Amazon price was the best I could find and although I asked for 1st class 3 day post it arrived the next day!

Bought a refurb one which helped save £, and seemed new. What’s not clear in tech spec or photos is that there is a label on the cigarette lighter that says limit to 150w (10a sockets*12v = 120w). This is fine for me as e-bike charger only draws 75w. Presumably the thinker cable/clips option needed if you want the full 300w. Seemed pretty quiet to me, but only had a short test, perhaps it gets louder if warmer over longer? The cable is pretty short, so if you are using cigarette lighter option, inverter will need to be close to the 12v supply. Its a cheap and easy option if fitting a formal inverter isn’t possible or easy.

I've been using it for a month - works as intended. There is a noise from the fan but I located it in a caravan cupboard so the noise is minimal. Having done a little research, it is best to match your inverter to the load you're using rather than buying a high capacity one as these are less efficient when using a load significantly below their capacity