A battery system for a head-mounted display is provided. A first arm member has one or more interior walls defining a first chamber, wherein one or more first batteries are positioned in the first chamber of the first arm member. A second arm member has one or more interior walls defining a second chamber, wherein one or more second batteries are positioned in the second chamber of the second arm member. A base member is coupled to the first arm member and the second arm member. The base member has a base member power connector positioned along an exterior surface. A first auxiliary battery removably couples to the exterior surface of the base member via a first fastener, the first auxiliary battery having a first side and a second side. A first auxiliary battery power connector is positioned on the first side and aligns with the base member power connector.