Review: Weller BP645EU battery-powered soldering iron

Our friends at Farnell recently sent us a Weller BP645EU battery-powered soldering iron to play with. We put it to the test and here’s what we thought…

The first impressions are good. It’s a nice, simple, product: throw away the instructions, install three AA batteries, remove the cover, slide the switch to on and hold the button for (near)instant soldering gratification. After faffing about with butane irons it’s a nice change. No lighters or gas refills required, no adjusting, just a single button. To quote a tortise: it’s easily turn off and onable.

Iron in action

Iron in action soldering an LED onto a Nanode

It takes a few seconds to get to temperature and then the solder flows well (we tested with 60/40 solder because we’re old school) and the tip works great. The warm up time is comparable with a butane iron but – and it’s a big but – there’s no locking switch. The button has to be held down for the iron to stay hot, if you let go to put the iron down to fiddle with the wires you’re soldering you’ll have to wait for it to warm up again. A hack in the form of a piece of sticky tape cross the switch would do the trick, but don’t forget to switch off when your done!

We tested the iron on a couple of little jobs around the lab, I installed an LED onto Peter’s Nanode and Tom L used it to bodge a new power supply into Martin’s BBC Micro prior to the birthday do. It worked fine for the Nanode LED job though it took a while. Reading the side of the iron explained the time taken: “6 Watts”. It took a while to get heat into the ground plane of the Nanode because of this. The iron struggled when Tom used it on the larger power terminals in the Beeb (he eventually moved onto a “proper” mains powered Weller iron (an antique, but similar Weller irons can be found here)).

The obvious use case is for jobs that would be a pain to do with a corded iron. It is ideal for car PC/stereo wiring, bike lights etc that sometimes need solding attention. It’s likely to be used for tweaks to the Hacklab CNC mill which is on the opposite side of the lab to the soldering bench.

Pros: Easy, cheap, uses readily available AAs, very portable.
Cons: Lacks locking switch, low power.

Conclusion: A good deal for the money, handy to have in toolbox for little jobs away from the mains. If you’re near the Hacklab then feel free to give it a go on an open night and see what you think (it lives on the soldering bench)!

4 thoughts on “Review: Weller BP645EU battery-powered soldering iron

  • I’d say it is good for low frequency remote work. Its shockingly fast at heating up (you have to push with your thumb to heat it up, with can be slightly cumbersome). If you were a pro though you would probably use a gas iron, but this is much cheaper than that option.


  • Where did you find Club Mate in Edinburgh? I *really* tried buying it when I was studying there but hat to import it from Germany …

  • i am having problems with dj excitement and was hope you could help me solder some contentions, let me know if you think you can help thanksa a lot jay.

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