The BA 30 from Sennheiser is a rechargeable battery pack for the evolution wireless D1 SK Bodypack, SpeechLine Digital Wireless SL Bodypack DW & AVX SK Bodypack transmitters (sold separately). It can be used to replace the four AA size batteries that power the transmitter-unit. The BA 30 uses a lithium-ion 3.7V 2030 mAh rechargeable battery.
Key Features
D1 SK Bodypack, SpeechLine Digital Wireless SL Bodypack DW & AVX SK Bodypack transmitters