T8001 Homebase - Battery Question

My Homebase 1 T8001, used to announce when it lost power, but in the last while it has not done anything. Would I assume that the battery has died, because when I unplug the unit, it does nothing any longer. Has any updates removed this function? I was always told on a power failure the camera’s would continue to record for a period of time unless the homebase battery dies. On May 21st we had a severe storm come through, and all my camera stopped everything once the power went out, so I have to think the homebase was not available.