USB Soldering Iron is Surprisingly Capable

We know what you’re thinking. There’s no way an 8 watt USB-powered soldering iron could be worth the $5 it commands on eBay. That’s what [BigClive] thought too, so he bought one, put the iron through a test and teardown, and changed his mind. Can he convince you too?

Right up front, [BigClive] finds that the iron is probably not suitable for some jobs. Aside its obvious unsuitability for connections that take a lot of heat, there’s the problem of leakage current when used with a wall-wart USB power supply. The business end of the iron ends up getting enough AC leak through the capacitors of the power supply to potentially damage MOSFETs and the like. Then again, if you’re handy to an AC outlet, wouldn’t you just use a Hakko? Seems like the iron is best powered by a USB battery pack, and [BigClive] was able to solder some surprisingly beefy connections that way. The teardown and analysis reveal a circuit that looks like it came right out of a [Forrest M. Mims III] book. We won’t spoil the surprise for you – just watch the video below.

While not truly cordless like this USB-rechargeable iron, we’d say that for the price, this is a pretty capable iron for certain use cases. Has anyone else tried one of these? Chime in on the comments and let us know what you think.

49 thoughts on “USB Soldering Iron is Surprisingly Capable

  1. I seen this video a few days ago and I am going to get myself one just to try out and keep as a backup. BigClive is one of my favourite Youtuber’s he always does decent teardowns of cheap Chinese electronics.

  2. And for the other end of the cordless spectrum, get a portasol (mini butane torch with soldering iron attachment). Will still pull this out for very large connectors and wire even when I’m sitting next to a pretty decent soldering station.

  3. I have one. Haven’t played around that much with it yet, but I gotta agree with Clive: with a portable USB battery, it’s pretty good for random soldering jobs. I keep the two of them in my laptop bag with a small amount of solder wrapped around the handle of the iron, we’ll see when it comes in useful.

  4. made one of these years ago from a radio shack battery operated iron. still works with the batteries but i can run it off of any powered USB port. Packed in my go bag with a 2w samsung charger. Gets hot faster than any standard iron i’ve ever used.

    1. He mentioned in one of his videos that people often comment on that. He says he didn’t even realise that it was remarkable; that it’s just the way he works because he used to have to make repairs on site so did it like this.

      It’s certainly remarkable to me!

  5. I’ve got one of these for about a year and it served very well. Surprisingly well. I have soldered a lot of loose wires in connectors, small SMD parts and other easy to break connections. And all that while being in the office, at least not at home where my regular iron is.
    It gets hot within seconds, powered from a USB battery it is semi-cordless.

    I can recommend this one, absolutely fabulous for this price!

  6. Does this actually work as well if you would plug it into a protected standard USB port of your computer? Specification for USB 2.0 limited the power to 2.5W (5V / 500mA), so i’m not shure what happens if you try overload these ports. Maybe the iron just has even less power available, or maybe you could damage your devices usb port if the circuit can not handle overpower?
    And maybe I’ve been burnt too much by bad soldering over my career, but any soldering iron without a somewhat precise, adjustable temperature control is a no-go for my toolset.

    1. The only thing that is USB here are the connector and the voltage. That allows you to use it with any USB adapter or powerbank.
      A proper USB port on a PC should shutdown when too much current is drawn.
      If it is less proper then it may overload some part, or supply the current with no problems from the PC’s 5V rail.

  7. I have one! Works great!

    I found that the touch switch for on/off only worked when I plugged it into my laptop (!). If it’s plugged into a mains USB power supply or into a battery pack it is always on, and it is not temperature controlled so it gets quite hot.

    1. It – or mine, at least – seems to be a bit temperamental about that, only switching off as it should when plugged into a battery pack. …which would sometimes refuse to work with the iron.

      As for plugging it into a laptop… ouch. They really do want 1.4A, you know…

      1. I had this same problem and solved it by adding a small contact right next to the ball bearing thing and grounding it. so now when i touch near the bearing i bridge the circuit and it works 100% of the time now.

    1. I thought about a LiPo powered portable soldering iron which uses Hakko tips with integrated heater and sensor. They are quite cheap from China. Weller is probably quite expensive. I also had a look on the Aoyue tips but they are also expensive. Like using a small RC-Lipo Pack, 2s to 4s, 1Ah to 1,5Ah and having a peak power of up to 80W with good regulation. With small electronics this should fit in the size of a pack of cigarettes (except the iron itself).

  8. I, too, belong to the butane/jury-rigged USB portable iron club and the more intriguing thing about this iron is the component teardown that he didn’t do – the tip.

    6 Watts distributed in a “usual” iron design would heat the barrel nicely and put nothing useful into the tip, whereas in this case they’ve got the heating element right where the action is, wasting nothing because there’s nothing to waste.

    Traditional designs are built that way because they’re easy to manufacture: Wind a heating coil, stick a thermally conductive tip through the center and who cares if you waste a few watts. This has been thought through differently and that’s worth considering, even if it’s a really mundane application.

    1. [BigClive] did mention that the heating element was in the tip. There is an advantage to having a larger mass of hot metal on the front of your iron, it’s that you effectively have more stored energy to dump onto your cold components and solder, otherwise you’d have to have a heating element that can output a lot more energy all at once in order to maintain its temperature.

    2. Actually the older bigger irons were using the bigger mass for thermal regulation. An analog based regulator circuit could get you 10-20 deg C of variation when the sensor was not really in the tip. Today you can put a greater power density on the tip (smaller tip, greater power) because you can stick a small enough sensor right where it should be, throw in a nice micro with 12bit of ADC and some fancy algorithms and you get better regulation.
      Example: my ersa icon nano gets 68W in a tip that is 2x smaller than your traditional 48W irons. It takes 10 seconds to heat up. If i remove the tip, i can see the heating element glow red hot for a few seconds at startup. But when i put a high spees IR thermometer on the tip…guess what: it never overshoots.

  9. First of all- I love Big Clive’s videos, Big Clive and Julian Llett are the best…
    I had a rechargeable soldering iron made by Ungar in the early 80’s and I truly miss it.
    It was red, had a small tip that heated up in about 2-3 seconds and an awesome drop-in stand for charging.
    I remember when it died due to battery age, I tried connecting the tip directly to various power adapters, not realizing at the time that it would require a huge amount of current. I wish I still had it today, I could definitely revive it using discarded laptop cells.
    Looked like this but with the stand and the tip doesn’t show in the pic:

    I think Weller took over Ungar and had similar products for a while but stopped making the small ceramic insulated (bi-metal?) tips ???
    Here’s a Weller pic- looks almost identical but I don’t see the awesome charging stand

    Looks like the unit Clive tested has a longer tip which I would think would require more power to heat up than the Ungar that had a very small tip that heated up very quickly.
    Maybe a good project for a 3d printer if the tips are still available

  10. I ordered 4 of them for the shits and giggles with some friends.
    Glad it can even do some work.
    You can buy ~4000mAh power bank with 5V/2A output for like 10 bucks.
    So for $14 you should have a very nice portable iron that’ll last a couple hours and can be recharged anywhere.
    Big fan pf Clive’s channel.

  11. I bought one a few months ago. Does the job really well and seems to be a bit hotter than the solder iron I already got. The tip size is great for soldering tiny stuff, like cable connections (micro USB) or smd components.You need to use a capable USB port (or power bank) otherwise the solder iron does not work properly. And oh, order some tips directly because today mine broke off (because everyday use and because of the intense heat inside the tip I think, something is glowing inside). I don’t understand the ‘button’, mine heat up without touching it. A good addition will be an on/off switch, to save the life of the tip and to avoid unnecessary power consumption (no need to unplug it each time, avoid USB port stress).

  12. Is AC leakage a problem with the soldering iron, or a problem with the power supply? Since it’s a “USB soldering iron” the use of a dodgy offline USB power supply is not the soldering iron’s fault.

    If the USB power supply has the USB connector shell connected to mains earth and the USB soldering iron has its tip connected to the USB plug shield then the tip should be at mains earth, as all good soldering irons should be.

    1. No. There are USB power supplies which offer more than 0.5A. 1A and 2.1 A are common, both as AC adapters (phone/tablet charger) and battery powered portable ones (power banks)

  13. Got one a few month ago just because it was cheap. I find myself using it a lot a forgetting my Antex (unless for bigger soldering jobs like those required to fix retrocomputers). I use it with a USB battery and it’s the star of the show in my local repair café.

  14. Got one off Taobao and I’ve been using it to learn to solder. So far it’s been pretty great for the price. It’s also very small so I can just store it in a drawer and it’s very easy to direct it exactly where you need

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