We have a Homebase 3 with a Eufy purchased 1Terebyte hard drive as part of a five camera kit deal. Installed it according to Eufy’s directions and have 4 SS330 cameras connected to the Homebase3. The free floodlight camera does not yet connect to Homebase 3, but that is supposed to be a future upgrade according to Eufy.
The expanded drive & Homebase3 are useless. It shows that the HDD available space is 100% but no recordings are stored on the drive. The recordings are only available on Live View. Tried both ethernet & wifi with Eufy reporting strong connections in both cases. Connections to cameras are strong on our 2G router. Getting a straight answer on this problem from Eufy tech support is evasive at best. We have given up on tech support. Essentially the Homebase 3 and expanded hard drive does nothing. Everything is done locally at the cameras. The solar cameras are great and have plenty of recording space, so you really don’t need the Homebase3 unless you want an interior alarm. The cameras send a notification alert to your phone when they are triggered. That’s plenty of alert for us. We have the Homebase3 interior alarm turned off, anyways. Homebase 3 is merely a unless box.
Homebase 3 Malfunctioning
It’s frustrating that the Homebase 3 and the expanded hard drive aren’t functioning as expected. Eufy’s tech support has been unhelpful. For now, the cameras handle everything effectively.
Did you get an answer to your question?
I also have only just purchased the Homebase 3, with mine the alarm went off and there are currently no devices attached to it. I am now concerned my Homebase will not work when I put a hard drive in mine. 
Update: According to Eufy Tech Support the Homebase 3 storage indicator “rounds up”. So when the expanded 1 TB harddrive has 99.1% of it’s space available, the Eufy Homebase3 hard-drive “space available” storage indicator “rounds up” and displays that 100% of the hard-drive space is available. Tech support says in reality the hard-drive can have hundreds of recorded videos stored on the hard-drive but the indicator will remain at 100% “space available” until the space is less than 99.1%. They say the recordings are so small that 0.9% of the hard-drive space can store hundreds of recorded videos. In that case, it could be years before the Homebase3 storage indicator shows that any recording are stored on the hard-drive.
It’s a Eufy provided 1TB hard-drive that was sent as part of a 4-SS330 camera, Homebase3, package deal.
Cameras are all active & have recorded videos. WiFi is stong and all cameras are shown as connected to the Homebase3. However, there’s is no way to know if recordings are stored locally at the cameras or at the Homebase3 hard-drive or both. I’m hoping both, but guess I need to wait until the Homebase3 Hard-drive’s “available space” gets below 99.1%.
At least that’s Eufy Tech’s supports story…