Hacker reverse-engineers and 3D-prints Sennheiser's overpriced BA2015 battery pack

An electronics enthusiast tears down Sennheiser's pricey BA2015 wireless microphone battery pack to discover it simply houses two NiMH AA cells and a cheap NTC temperature sensor. Frustrated by $80-$100 official replacements, they design a 3D-printed clone in OpenSCAD using flat-top Panasonic cells, a paperclip for the series connection, and a tiny magnet for the positive terminal. The project demonstrates that the pack's 'smart' charging features actually live in the microphone, not the battery, though the author concedes the DIY version is flimsier than third-party alternatives. Complete OpenSCAD source code is included for others looking to avoid the official markup.