You’ve surely seen the TS-100 soldering iron. It has an OLED display, an ARM processor, and will run with an external battery pack. They are not too pricey, but at $80 or so they aren’t exactly an impulse buy, either. [Drone Camps RC] used one in the field and decided to try a Hakko FX-901 instead. He did a video review that you can see below.
The FX-901 is about half the price of a TS-100. Granted, it doesn’t have a fancy display and you can’t hack it to play Tetris. However, it does take batteries (including rechargeable) without an external pack. The manufacturer claims up to two hours of use and that it will melt solder in 40 seconds. From the video, the iron actually melted solder in under 30 seconds. The two hours, by the way, is with rechargeables. Alkaline AA batteries should give about 70 minutes of operation.
In addition to showing the unit and doing a few tests, [Drone Camps RC] also shows several common soldering jobs with the iron. It seems to work very nicely. He also looks at some much less expensive alternatives, but all of them had some issue like not heating quickly enough.
If you really need temperature control and programmable profiles, this isn’t your iron. But most of us went decades without any sort of fancy stuff like that, anyway. If you really want to see what’s going on with the TS-100 though, we did a review. If you want to build your own, there’s always this ugly iron.