Disclosed herein, among other things, is an apparatus for connection to a hearing assistance device having a DAI compatible interface compatible with direct audio input (DAI) signals. According to an embodiment, the apparatus includes a connector to connect to the DAI-compatible interface. The connector includes audio and ground connections compatible with the DAI-compatible interface. The connector further includes a power connection adapted to provide power to the hearing assistance device. The apparatus also includes a power source electrically connected to the connector. The power source is adapted to charge one or more energy storing devices, such as batteries, within the hearing assistance device, according to various embodiments. In an embodiment, the power source is adapted to supplement power provided to the hearing assistance device by the one or more energy storing devices within the device.