portable soldering iron powered by usb cable?

So I have been looking for a soldering iron that I could take with me in my backpack that wouldn’t need high power.

I was thinking about a butaan gas soldering iron or even one powered by 5volts through usb.

Does anyone have any experience with one?

Not to do mayor work just light repairs, like resolder broken connections and such.

Depending on how much you are going to spend on the iron, check ebay for “TS100 Electric Soldering Iron”.
That solder iron can run on a laptop power supply or a car battery.

You will need about 25 Watts to have useful soldering iron.
This would mean 5 Amperes from a 5 Volts power source like a power bank.
So you can forget about that.
I think you’ll want one on butane gas (refill with lighter butane (aansteker gasbus, je weet wel…)
Don’t buy the cheapest ones (like i did…), they will disappoint you.
I’d say spend around $ 30.— (or more) on one that has good reviews.

Soldering irons are usually around 40 watt. A USB port is rated at 2.5 watt max. Of course some USB ports MIGHT deliver more, but the spec only calls for 2.5 watt. So the idea is a no-go.

Depends.
For electronics it’s usually lower, sometimes less than 20 Watts (or it has a thermostat).

Power banks usually have a 2.1 A output for iPads, but that’s still only 10.5 Watts.

Got a battery one from lidl for £5 awesome

That is where my MIGHT comes in, but honestly that’s not really Universal Serial Bus as it was designed, it’s just a power supply hack that has become popular.

For example, if I wanted to sell a “USB” soldering iron, it would have to work on the 2.5 watt spec so that it worked on ALL USB ports. It’s not really USB if you can’t use it universally.

USB type C will make it possible. The spec allows for up to 5A at 12v (60W) or 20V (100W).

Butane will work on a circuit board and do heavier jobs. I carried a butane Weller soldering iron for a couple of years on vehicle launch programs. No need to try to find an outlet and they heated very quickly. I used one to regularly splice 12 gauge copper wire with no problems.

I kept a can of butane handy and never had any worries. I last used one about two years ago after it was sitting on a shelf for about five years. Mine fired right up. If you’re using it for camping, you might find other uses too: starting a camping fire, cauterizing a cut, hot knife for cutting rope, deicing a frozen lock, etc.

I agree the butane torch with a soldering tip is the way to go. They heat very fast and work well. Just be careful the tip attachment doesn’t fall off when it’s strap heats and expands. It can dump off and burn you.

I’ve had one of the Bernzomatic pencil torch/soldering irons for many years now, used it a lot and in terms of portability it’s probably the best you are going to get on balance. Comes with a nice little case you can stash a lighter to light it and holds the catalytic iron attachment and tips. In general they are pretty reliable although I’ve had to adjust the output slider once which is pretty easy. Generally speaking I really don’t have many complaints, it certainly does make enough heat to do some pretty serious soldering. You do have to be careful you put the catalytic vent upward from it’s little stand or it will burn your table. And unlike an iron you can easily use it for heat shrink (you can just use the catalytic vent without switching it to torch mode) and if you need to do some serious soldering on something heat resistant you can just use it in torch mode. Butane life is quite good and you can turn the power down and up easy enough so you can leave on in low mode to save gas and keep it warm so save relighting it. Burn stability is also very good, much better than Chinese jet lighters I’ve used.

All that being said as HKJ suggested the TS100 may be another really good option. It uses the integrated heating element tip system that is far superior to the heater in tip design. I have a AOYUE 2930 that uses the same tips and it heats up super quick and really maintains heat well. If I had not got the 2930 I probably would have gotten the TS100 to replace my benchtop station. That being said I don’t know anything about the build quality and it is a lot of electronics in a small package. You also of course need a power pack to go with it but even with that would be pretty small and it would be way better for fine delicate work because you can get small tips, have much better temp control, and doesn’t have a hot exhaust gases shooting out one side.

Interesting.
What kind of battery does it use?

Well, it seems exist:

According to the reviews it works, which made me curious, so I ordered one.

I had it on my wishlist for some time, but what are you gonna do with 8 Watts?

My portable soldering iron of choice is the battery powered Hakko FX-901. It uses 4 AA batteries and gets well over an hour of continuous use with Eneloops. I’m sure it blows away any USB powered soldering iron out there. IMO, it’s well worth the price. BTW, I bought a screwdriver tip which is larger than the original conical tip it came with. Works great. I was able to tin and solder 12 guage wire with it no problem.

This is the guy that you should listen to about electrical things, and he says it isn’t half bad!

I know it shouldn’t work, but all those reviews (over 300 of them) claiming that it does compelled me to keep an open mind and try myself.

I’ve been subscribed to his channel for the past year. He really does know his stuff

I could be good for SMD electronics.
Either way, i still think it’s a cool little thing, but… well… 8 Watts…