Cloning a Sennheiser BA2015 battery pack

Sennheiser's BA2015 battery pack for wireless microphones costs $80-100 despite containing only two standard AA NiMH cells and a $0.02 temperature sensor, making it one of the most expensive AA battery packages available. The author reverse-engineered and is cloning the battery pack because third-party alternatives are significantly cheaper, and the actual components cost roughly $5-6 to manufacture. The proprietary design exists primarily to prevent users from inserting non-rechargeable alkaline batteries into the charging dock, though the author argues this justification doesn't warrant the premium pricing.