For filmmakers, stopping to swap out batteries isn’t always an option. But when that red light is flashing, and your camera battery is dying, something must be done. Consistent camera up-time is critical in video, time-lapse, and on a long photo shoot. A pause to swap out batteries can mean a missed shot and wasted time on set. Never miss a moment again with the Case Relay from Tether Tools, a first of its kind, this innovative device provides uninterruptible power for a DSLR or mirrorless camera using any standard 5V USB external battery pack.


Burning Boat Media are filmmakers from Copenhagen, Denmark created the above tutorial featuring the Case Relay Camera Power System. In the video, they’ve rigged their Sony A7R II with two 15mm rods, a Tether Tools Case Relay Camera Power System, camera coupler, and two external USB battery packs to provide 12 hours of power to their camera.

If you’d like to mimic this setup, you’ll need a couple pieces of gear. In addition to the Case Relay which is the heart of the system, you’ll need a dummy battery for your camera. The Relay Camera Coupler goes into your camera battery port and attaches to the Case Relay to power the camera.

Please note that the coupler is camera specific.



Case Relay Benefits:

  • More cost effective than purchasing multiple proprietary camera batteries
  • Easy to hot-swap batteries or power without needing to stop shooting.
  • Power sources are non-proprietary. Power your camera with the same 5V battery you use to charge phones or tablets.
  • Never need to charge camera batteries again. And never run out power.
  • Compatible with most Canon, Nikon, Sony, Panasonic, Fuji, and Olympus cameras.


Case Relay Uses:


  • Extended shoots in the Studio
  • Time-lapse
  • Astro photography
  • Long exposures 
  • Any time you need more than one battery