LipoSolder is a battery powered portable soldering station, which does not have the usual problems of portable soldering irons.
The LipoSolder station is powered via an XT60 connector from regular RC batteries (with 3S or 4S). A step-up converter generates a voltage of ~30V for the soldering iron, which is controlled by an AVR microcontroller via PWM.
A PID control loop in the code ensures stable temperature regulation and very fast warm-up times.
The big advantage of this project is that a normal soldering iron is used, which is actually intended for the soldering station ZD-931. These soldering irons are very cheap, powerful and easy to use. The only disadvantage of these soldering irons is the used Type-E thermocouple. Corresponding AD-converters are available, but difficult to purchase.
The soldering station can be operated via the OLED display, which is connected to the MCU via I²C. The source code is (as always) open source: https://github.com/Manawyrm/LipoSolder
In recent years, soldering irons like the TS100 or TS80 have made this project obsolete.