3s Battery for Soldering Iron

When I got a TS80p soldering iron, I immediately assembled a three-cell battery for it, it turned out to be much more convenient to work autonomously.

And in operation, such a battery lasts for a long time. But I am like a "princess and a pea", everything is somehow wrong, .. well, as usual. Therefore, a month ago, the idea was born to make it more ergonomic, without protruding wires, without a monitor that dangled nearby, and you can't work without it either, because discharge control is necessary for Li-Po batteries, otherwise the cells can be damaged with a deep discharge.

In this design, I placed in the case both the elements themselves and the voltmeter-monitor, signaling a critical discharge. In the firmware of the same TS100 soldering iron, it is possible to turn off the power consumption when running on battery power, and in the new version, the developers decided to implement automatic switching to low consumption, that is, the TS80p can work not only from 12 volts, but also from 9 and 5 volts, of course with less current. Therefore, in my case, I need an external monitor. Although it would be possible to get into the firmware and rewrite or add the desired function, but I have not yet reached it thoroughly...

I changed the voltmeter-monitor myself a little by removing very loud buzzers and installing one quiet and small one. I also painted it lightly with acrylic white paint so that it would not show through with a black spot through the body.

And in the standard version, the buzzers simply would not fit in the case. The digital indicator washed off the black paint with technical gasoline. However, it happened by accident when I was washing the remnants of the adhesive foam backing on the PCB. And since the indicator turned out to be white, I decided to install it in the case in the light through a 0.2 mm layer of plastic.