The cirBATTverter turns the energy of a second-life lithium battery into usable AC power. We publish all of it: KiCad sources, build documentation, and our own technical review — including the faults we have not fixed yet.
We would rather publish an honest project than a showcase. This revision carries known faults, documented in the open, which must be fixed before any board is built or powered up.
Conversion happens in two stages, driven by two separate controller modules.
A first transistor bridge chops the battery’s DC into high-frequency AC.
The windings are etched into an 8-layer PCB. It steps the voltage up to a DC bus of about 400 V.
A second bridge chops that bus with sine-wave modulation, driven by an off-the-shelf EGS005Q module.
A filter stage smooths the switching before the 230 V output. Its sizing is one of the points still to validate.
The documentation aims to stay readable by someone new to power electronics. Powered testing, however, calls for a trained person.
The project is released under CERN-OHL-S-2.0. You may study, modify, manufacture and sell it, including commercially.
Bench measurements, build reports, schematic corrections: contributions go through GitHub. For an industrial integration, cells or a BMS, let us talk directly.
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