There is nothing worse than doing an extended shoot and suddenly running out of power in your camera battery. Inevitably, it’ll happen right when the mood is perfect and things are finally going exactly as you wanted. In a recent example from my life, I ran out of power while making a timelapse of the complete solar eclipse. I was shooting over the Tetons in Idaho at the very center of the eclipse…and I’ve got nothing to show for it.

Had I been using the Case Relay from TetherTools, that never would have happened.

Simple utility

The Case Relay does two things for your battery power. First, it contains a battery in the unit, so there’s always power going to your camera. Second, it allows you to plug your camera into any USB power source to keep it running. Any USB power source, from a little battery pack to a laptop to power directly from an outlet. Because the unit has a battery in it, you can even hot-swap sources so that when your USB battery dies you can plug in another one without interrupting camera function. Tethertools also offers a USB battery, which is very good. Continuous power that never runs out. It’s cool.

They have a unit that is made specifically for your camera which replaces the battery in your camera — the Relay Camera Coupler. This plugs into the universal Case Relay, which plugs into the power source. Oh, and the Case Relay automatically tops off its internal battery when it’s plugged in so you can hot-swap anytime. You can use the same Case Relay and just get a new Relay Camera Coupler for your various cameras.

Why do you need it?

The Case Relay replaces A/C adapters for your camera and does a better job of keeping you powered. When would you use this? Here are some instances when I’d use it:

  • Shooting time-lapse
  • Extended shoots in the Studio
  • Anytime I shoot tethered
  • Astro Photography
  • Long exposures at night
  • Anytime I shoot video
  • Anytime I think I need more than one battery



If you’ve ever run out of power during a shoot, you know how much trouble it is and how it weighs on your mind before every shoot in the future — especially if you were doing something like video or time-lapse that can’t be interrupted by swapping batteries. TetherTool’s Case Relay solves this problem elegantly and simply. Highly recommended.