If you are an owner of any of the A7 line of Sony cameras (A7, A7R, A7S, A7RII, etc) then you know that battery life comes at a premium, especially if you are doing anything that involves shooting video or taking timelapse photos. I know from my own personal experience when using the A7R for video, I could never have enough batteries on hand. I can’t imagine how my camera would have enough battery power for something like an all-night timelapse shoot, especially if I needed to leave the camera unattended for hours on end. I’ve wondered for a while how to deal with this issue, and I’ve run across a solution: External battery packs!

You’ve probably seen at least part of this solution already. You know those portable power banks that can be used to repeatedly charge your devices while you are traveling? With this solution, that’s going to be your camera’s battery. All you need are a few more items and you are in business. The really cool thing is that the Case Relay Power System allows the battery to be hot swappable! So for shoots that are going to be extremely long, you could pick up a few extra power banks. I do want to point out before I go any further that this solution is not ideal for shooting anything where you’ll be moving around a lot, like street or sports photography. It might work, but you might also find the whole setup a bit cumbersome. However, for situations like shooting timelapse photos, recording interviews, or any situation where you’ll be using a tripod and won’t be particularly mobile, this is a great solution.

The setup that I put together utilizes these four pieces of equipment (around $187 total):

Here’s how it works:

If you are using a tripod, the first thing to do is attach the Tether Tools StrapMoore to a leg on your tripod, as shown below:

Tethertools Strapmoore

Next, grab the power bank and the Case Relay Camera Power System. For my setup, I stacked the Power System on top of the power bank (in the middle), then holding both together, wrapped the TetherTool’s StrapMoore’s strap around them. The power bank and Power System are held in place both by the StrapMoore’s strap as well as the heavy-duty GripperElastic that the StrapMoore is lined with on the inside. The StrapMoore can hold up to two pounds without a problem.

Once attached, you’ll have both the power bank and the Case Relay Power System fitted snugly to your tripod leg via the StrapMoore. Go ahead and plug the USB cable from the Case Relay Camera Power System into any of the available USB ports on the power bank. Once that’s done, your setup should look similar to what’s shown below:

Strapmoore with Case Relay

The only thing left to do now is attach the Tether Tools Relay Camera Coupler and plug it into your camera where your original battery was. Keep in mind that in order for this to work, you’ll need to remove the battery door on your camera body. Shown below are both ends of the Camera Coupler plugged in:

Camera Coupler Plugged in Camera Coupler Plugged in

Once the Camera Coupler is attached, you can turn your camera on and enjoy hours of hot-swappable battery life! The image below shows the completed setup.

External Power Supply-full

I haven’t done any benchmark testing to see exactly how much longer my battery life is with this setup, but I’m expecting it to be significantly longer. I did shoot around 30 minutes of video recently using this setup as the power source and had no problems – the battery had plenty of life left after 30 minutes of shooting.

I wrote this post with Sony users in mind, but Tether Tools makes the Case Relay Camera Power Coupler for several different camera manufacturers. So if you are a fan of Canon, Nikon, Olympus, etc. – fear not! This setup will work for you too.

A couple of side-notes regarding this setup:

  • I noticed that my camera never really shows an accurate reading of how much battery life is left in the power bank. Fortunately the power bank itself has five lights indicating how much battery power is left. No more lights on = no more power.
  • Be careful and be sure to have a firm grip on the power bank and Power System when unstrapping the StrapMoore. The power bank is deceptively heavy and the surface on the EasyAcc (the brand I used) is a bit slippery.

Overall, I’m loving this setup for any type of “battery intensive” shooting. Hopefully this helped you out too!