3. While it can replace a hardwired doorbell supplying 8 24 volts of electricity, its rechargeable battery means you could put this doorbell anywhere. And the optional Ring Chime add on can even sound an audible chime inside the house, just like a traditional doorbell would. RemoBell also runs on batteries and can be installed anywhere. But it doesn't connect to existing doorbell wiring, which means the doorbell won't chime inside the house, only on your smartphone. The August Doorbell Cam requires 16 24 volts of electricity and can replace only a wired mechanical doorbell. Field of View: Do you want a narrow view of just the person at the door, or do you want to see everything around your entryway?The Ring Video Doorbell 2 and Ring Pro boast 160 degree viewing angles, which let me see my whole porch and driveway. The RemoBell and August Doorbell cams have tighter angles, of 120 degrees. Video Resolution: The higher the resolution, the sharper the image, which will make it easier to identify people at your door. Both of Ring's doorbells record video in 1080p, while the RemoBell and August Doorbell Cam record in 720p HD. August's resolution is actually 1280 x 960, but that's not quite "full" 1080p resolution.