Here’s a professional overview of the Tether Tools Relay Camera Coupler – NP‑FW50 (Model CRSFW50):
Tether Tools Relay Camera Coupler for Sony NP‑FW50 (CRSFW50)
What It Is
The CRSFW50 is a dummy battery / coupler designed to replace the Sony NP‑FW50 battery in compatible Sony cameras. When used together with Tether Tools’ Case Relay / ONsite Relay Camera Power System, it allows your camera to draw continuous external power (USB / wall / battery bank) rather than relying only on the internal NP‑FW50 battery. The coupler has no battery itself — it just routes power through the Relay system. Tether Tools+2B&H Photo Video+2
Key Features & Specifications
| Spec | Details |
|---|---|
| Model / SKU | CRSFW50 Tether Tools+2Tether Tools+2 |
| Battery Replaced | Sony NP‑FW50 Tether Tools+1 |
| Compatible Cameras | Many Sony models using NP‑FW50, including but not limited to: a7, a7 II, a7R, a7R II, a7S, a7S II, a6000 / a6300, a5000 / a5100, a33 / a35, NEX series, RX10, ZV‑E10 etc. Tether Tools+3Rockbrook Camera+3B&H Photo Video+3 |
| Coupler Cable Length | ~ 10″ (≈ 25.4 cm) from dummy battery to the power input jack. B&H Photo Video+2Rockbrook Camera+2 |
| Total Cable Run with Relay Cable | ~ 50″ (≈ 127 cm) when used with the Relay extension/power cable. Tether Tools+2Rockbrook Camera+2 |
How It Works
Insert the CRSFW50 coupler (dummy battery) into the camera’s battery compartment in place of the NP‑FW50 battery.
Ensure the camera’s battery door can fully close, routing the coupler’s cable through the rubber trapdoor or cable exit if present. Rockbrook Camera+1
Connect the coupler’s barrel/coax female input to the Case Relay power system (external power source, USB battery bank, wall adapter etc.).
Because the Relay power system includes a 1200 mAh internal buffer battery, you can swap out the external power source without the camera losing power. Rockbrook Camera+1
Benefits
Enables continuous power for long sessions: video, time‑lapse, photo booths, live view, etc. Tether Tools+1
Reduces the need to carry many NP‑FW50 batteries. External power sources tend to be more accessible and often cheaper/ more durable.
Consistency and reliability: the buffer allows hot‑swapping external packs without interrupting shooting.
Flexibility: the same power system can work across different camera models by swapping couplers.
Things to Keep in Mind / Limitations
The coupler itself has no internal battery storage; continuous power depends on the external supply + the Relay system’s buffer. If both run out, camera loses power.
Cable routing matters: forcing the battery door, improper routing can damage cable, dummy battery, or the door/trapdoor.
In high power‑draw modes (video, live view with lots of sensor/processor use), make sure the external power source and cable gauge are high quality to avoid voltage drop or instability.
Verify compatibility for your particular camera model (battery door design, presence of trapdoor, voltage requirements etc.) — even among NP‑FW50 users, some gear may vary.
If you like, I can draft a marketing‑style product description for CRSFW50, or compare it to some competing NP‑FW50 dummy battery / power couplers so you can pick what works best.