Leave Your Camera Batteries at Home With the New Case Relay System

Leave Your Camera Batteries at Home With the New Case Relay System

Recently, a gear company you may be familiar with, Tether Tools, released their new Case Relay Power System (CPS). This contraption allows you to shoot continuously without any interruption or having to keep recharging batteries. So, I decided to put it to the test and travel almost 100 miles away with just the power system and no batteries.

The System

Like I briefly mentioned, the Tether Tools Case Relay System allows you shooting with your camera continuously without any interruption whatsoever. The concept behind the system is that it gives you piece of mind if you're shooting a time-lapse, on-location, or during your studio session. This abolishes worrying about forgetting batteries, batteries losing power, or having to switch them out mid-shoot. The Case Relay CPS also comes embedded with a secondary power source in case your external source runs low that we will look at in detail later in this review.

How It Works

While it may look complex at first glance, it's actually quite simple. The Case Relay system needs a connection of three components in order to work. Here is how it's put together:

  1. Case Relay CPS ($99) 
  2. Camera Coupler ($30-35) (compatible with your specific camera)
  3. Rock Solid External 5V Power Pack ($49) or Wall Outlet Adapter ($10)

These accessories are either sold as a bundle or separately. It’s very easy to put together: simply insert the camera coupler into your camera battery port, attach the coupler to the CPS, and connect the CPS to any 5V external battery or an AC power source (wall outlet). 

The Case Relay CPS

The Relay CPS acts as the "heart" of the system that connects the power source and camera itself. It has a light that turns green when connected and powered; it's pretty simple. It has its own secondary embedded 1200 mAh battery in case your external source runs low or you lose power for any reason. This embedded source assures you continuous power and peace of mind. 

Tether Tools offers StrapMoore accessories separately to help secure your CPS either on your belt loop or on an object such as a tripod. 

The Camera Coupler

The coupler is the piece that you place into your camera's battery slot. They offer an array of different couplers that are compatible with \ your specific camera and battery mold. The coupler connects to the Relay CPS, after which you will never need to charge conventional camera batteries again. The coupler is compatible with most Canon, Nikon, Sony, Panasonic, Fuji, and Olympus cameras. You can check to see yours is compatible here

The RockSolid Battery Pack

This is the meat and potatoes of the whole system. This high capacity 10,000 mAh external battery connects to your CPS and gives the whole system its power. I will get into how "rock solid" this pack is, but it is amazingly simple how to work this thing. All you do to turn it on is slap it, and a green light should turn on. Green represents high power, orange is medium, and red is low power.

The Rock Solid rechargeable battery pack last 3-10 times more than the conventional camera battery. Not only does it allow you to charge the Case Relay CPS, but it also charges devices such as tablets, smartphones, or any other USB-compatible device. During my trip of three half-day sessions, my battery pack was still at half power by the time I was finished, which is great! 

The power bank contains a rechargeable lithium-polymer battery and a microchip that controls the voltage when recognizing the device needs to be charged, ensuring the device will never be damaged.

Build Quality

The Relay and Coupler are both plastic, so it would be interesting to see how these hold up to the test of time. I could see this being an issue if you are rough with your gear, but other than that, these should be just fine.

The Rock Solid external battery pack lives up to its name; it feels bulletproof. It is made of aluminum, the same material as Apple's Macbook Pro shell. It is very sturdy and not too heavy and fits into a back pocket quite nicely. 

What I Liked 

There're a few things as a natural light portrait photographer that I liked.

  1. Easy Setup: To start off, it is extremely easy to put together and figure out. At first, I was worried that I'd have trouble putting everything together properly, but it is very simple. 
  2. Seamless Battery Power: I really liked how I went through three portrait sessions without having to charge my batteries or worry about them. It is very impressive that my battery pack didn't even lose half its power. 
  3. Rock Solid Multiple Uses: Not only does the Rock Solid battery pack power your Nikon D750, it can also charge up your iPhone, iPad, Kindle or any USB-compatible device.
  4. Options: Another advantage of the Case Relay is that you're given options. You can either go portable with the battery pack or plug into the wall with their adapter.
  5. Great for the Forgetful (Like Me): Sometimes, even when you go through your checklist twice, something goes missing: just in case it may be batteries, this would be a great backup in any photographer's bag. 
  6. Must Have for Landscape, Astrophotographers, etc.: This product I see being a very useful tool for landscape, astro, or any other photographers who shoot over elongated periods of time. With it, you won't need to worry about swapping batteries or losing power. 

What Could Use Improvement

I only have one qualm, and this isn't exactly something I didn't like, but while it is a nice, well-built product, I don't see it as an absolute necessity in my specific genre of photography. 


The Case Relay Camera Power System works as exactly advertised. It allows you to seamlessly use your camera without the interruption of switching batteries or losing power. The CPS exceeds the power of a conventional camera battery by 3-10 times. It gives you the flexibility of using an external power battery source or being plugged into a wall. I can see this being a great tool for photographers out there who travel, camp, or hike, as well as those who create landscapes, timelapses, or do astrophotography. It worked great for my recent trip out of town and gave me peace of mind. Pick yours up here.


Nick Pecori's picture

Nick Pecori is a Florida-based advertising photographer who has shot for clients Acer, Bealls, Shoe Carnival, the Florida Lottery, etc.

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I rarely find myself needing to swap batteries. I am an events photographer and I am provides with batteries for the company's 5Dm2. It's able to last the whole night of 3 assignments from concerts, night clubs, or the simple social parties.

And even on my personal camera, D810, I use EN-EL18a which packs more juice. I shoot portrait and fashion sessions with it that mostly last for 12+ hours and still has some charge left.

The product is not a bad idea anyway, though that's enough of dangling wires for me. Time lapse photographers will surely enjoy this one!

I am not quite clear on how you are able to shut the door with the cable coming out of the coupler. Does this require a modification to the camera?

I believe it is so thin that it probably just get's pinched between the hatch?

It depends on the camera. Some cameras (for example I'm pretty sure the D750 does) has a small "doggie door", that you can open to let the cable out.

Exactly what Donald said, there's a small door that can open for the wire on my D810.

That's interesting - my d800 does not have such a door.

It has. Look on the side of the grip

Oh wow, I just checked, that's well hidden! Thanks Fritz.

I just checked, my Sony a6000 has a little "doggy door" for such a cable, too.

I have never noticed it before and would not have believed it existed if I hadn't seen if for myself!

Ha ha this would be a must with sony cameras :)

I have a battery grip on my Canon and it seems to last at least 2 days of heavy shooting. My Sony A7s on the other hand is a complete battery hog and stinks, I have 5 back up batteries, so this, if it works with Sony might be nice for Video shoots with the Sony's. On a side note, does anybody have any idea of an external battery supply for a MacBook Pro retina? That does not cost more than the laptop itself? I have often wanted to shoot tethered on location where there is no power or have an emergency back up power supply for my laptop..
Love your all's articles by the way. Nice work!

Check out a company called GoalZero, they have several options for powering anything with a powerchord, like a macbook pro.

I carry 3 batteries for my D800. I almost never have to even switch to the second. This would be a cooler concept if battery life was a big problem but I can shoot all day on one battery so long as I stay out of live view. (which I'd almost never use anyway)

I suspect this would be more useful for a d800 for extensive video use than stills shooting. I use live view on my d800 a fair bit and still almost never need to pull out the second battery.