USB to DC 5V to 12V Voltage Step Up Converter Cable - 3ft/1m, DC Jack 5.5 x 2.5mm or 5.5 x 2.1mm, USB Charger

Very hand adapter to fit my Masterbuilt gravity 800, allows me to supply it with a power bank.

Nice units, They don't feel like they will fall apart anytime soon as some alternative devices I looked at reviews of are reported to. The 5.5 2.1 to 2.5 plug adapter is a nicely made unit too and in my head it's worth a £1 or 2 on its own !I bought 4 of these so I hope that counts as a reasonable sample to test. I did see a small variation in maximum power output between them on test but nothing too bad.Looking at the figures for the 'least powerful' of them (obviously others test methods and results may vary etc etc ) they produced about 9.25Volts (highest 9.35) without load and all stayed above 9V as the load was applied and increased to 0.5AAfter that I saw 8.4V (still fine for many 9V devices) with 0.6A drawn and then down to 7.3 V with 0.73A drawn.For the very best of my 4 units the final result was 7.7V with 0.78A drawn (with 5.08V @ 1.48A going in)I didn't take it further but I did leave the least powerful one delivering 0.73A for 3 minutes with no significant noise or heat building in that time.So this works well for producing 9V up to around 0.5A (500mA) and with a good bit left in reserve for heavy initial current in lights /chargers etc.For what they are and the excellent price I'd say these are a useful problem solver for things like device chargoing in the car etc

This device works well so far. I've only briefly tested it with four 12v fans with a current draw of 0.08A each. They're pulling a total of 0.37A consistently when powered using this cable and a OnePlus fast charger which can provide up to 5A. Will report back when I've tested it using different power supplies. Listing says it needs a minimum of 2A to even work so I'll see if that's true. It does get noticeably warm in my use case but so far doesn't seem to be overheating when given sufficient power, some heat dissipation is normal given the job its doing. Connector seems stable, cable seems fit for purpose. I don't think this circuit is a difficult one to manufacture but to get a reliable one that doesn't overheat, ya do have to spend a few more quid. Avoid getting those 10 x boost converter module packs as they tend to overheat massively and can output very little current. Would recommend this cable so far!

I work with network equipment and often have to use small Netgear switches or media converters in racks or whilst moving about. There are often no mains sockets available. This lets me power the switch or media converter from my laptop, or even a convenient USB port on the equipment itself, like on most Cisco gear.You do need to check it won't pull too much current, but it's fine for most reasonable use cases.Robust enough as well. Maybe my only complaint is the electronics are all in the plug, which is quite deep. This sometimes means you can plug it or leave it plugged in with limited space. If it was in a blob on the middle of the cable, you could do this.I tried another type of this cable before and it was not nearly as robust or stable.

Ideal for what I wanted

Great item when you need a 9V supply without using or buying a bulky mains adapter. Simply plug into an available USB port or into a powerbank and away you go. The cable is nicely flexible.

Doesn’t seem to output enough power to run a British Telecom FFTTP.Keep getting drop out’s when using…

I had really high hopes for this product. At first it seemed it would work well for powering my ATEM Mini, the Mini booted up, all the buttons lit up etc. However, after a couple of minutes the signal dropped and the Mini started making a warning sound, so I quickly unplugged the device. I assume there was a problem with the amount of power getting to the Mini so decided to return the cable. I have nothing else to try the cable with so cannot say if the cable was faulty or just not compatible with the ATEM Mini.