One of the things about the FX9 that makes no sense is it’s external DC input. When you are using just the camera body the FX9 requires a rather odd-ball 19.5 volts to power it via it’s DC in connector. Most cameras have a 12v to 16v input range so they can be used with the multitude of V-Mount or Gold Mount batteries that are common place in the world of professional video. But not the FX9.  The FX9 is also fairly power hungry so the standard BP-U batteries can be a little limiting, especially if you also need to power any accessories as the camera doesn’t have a power output. A V-Mount battery will run the camera for a long time and they generally have D-Tap power outlets, but they are the wrong voltage for the FX9s external input. So if you want to use a V-Mount battery, as I do, then you need not only a mounting plate but also a voltage converter.

The adapter I have chosen to use is manufactured by Core. Why this one? One thing that was important for me is not only to be able to power the camera from a V-Mount battery, but also to be able to power it from a standard external 12 volt power supply such as found in most studios, or something like a car battery. The Core CXV-FX9 adapter includes a voltage regulator that takes the 12 to 16 volt range of a typical Lithium battery and converts it to the 19.5v needed by the FX9. It also has an industry standard 4 pin XLR connector that you can use to power the camera from a 12v external power supply.

Hot Swap:

If you have a power supply connected to the 4 pin XLR you can hot swap the V-Mount batteries. If you have a battery on the adapter you can hot swap to and from the external power. During hot swapping the adapter not only continues to feed the camera with power but also the 2 D-Tap ports on the adapter remain powered.

Low Battery Warning:

One issue that all these adapters have is that they have to convert the battery voltage up to 19.5 volts and this is what is fed to the cameras DC in connector. This means that the camera has no direct connection to the battery, so it has no way to know the charge state of the battery. All you will see in the viewfinder as an indication of the output of the voltage converter. This will remain at a constant 19.5v all the way until the battery is flat and cuts off, at which point the camera will just die. That’s not good, if you are halfway through recording something it could corrupt your media. You won’t have any warning in the camera of the battery going flat.

To try to address this at least in part the Core adapter has an LED light on the operators side that is green when the battery is well charged, but turns to red when there is only around 10% of the batteries capacity left. This does at least give some warning of a battery about to die.

As well as the adapter, I’m trying out a couple of Core’s Hypercore Neo Mini batteries. These are nice, compact 98Wh batteries. They are UN Tested and certified so meet all the requirements for air travel. These batteries have a clever LCD display that displays the available run time of the battery. This is much more advanced than a simple charge indicator (it has one of those too). The battery actually detects the load being drawn from it. It also knows the exact state of charge of the battery.

Using these it is able to calculate with great accuracy how long it will be before it will be flat. I have found this to be remarkably accurate, typically to within just a few minutes. I’ve been using this display to let me know when I need to start thinking about changing the battery. It’s accuracy gives me the confidence to continue shooting until I’m down to the last few minutes of run time. Typically I’m getting around 2.5 hours without the Atomso Ninja recorder and just under 2 hours with the Ninja from one of these excellent little batteries.

Attaching the adapter:

Attaching the adapter to the camera is easy. It uses the same mounting points as Sony’s XDCA extension unit. So there are lugs that slide into slots inside the FX9’s battery compartment as well as two small bolts that attach it to the top of the camera. This makes it incredibly secure with no wobble or other movement. I would have no concerns about supporting the entire camera rig from the battery adapter or adding perhaps a V-Mount wireless video link and then large or heavy batteries behind that. It’s very secure and it looks like it’s meant to be there. Another nice touch is that as well as the 2 D-Tap power ports on the top of the adapter there are also 3 additional 1/4″ mounting points for accessories such as monitors or wireless receivers etc.

I do have one small criticism. The position of the D-Tap ports is quite close to the edge of the adapter. If you are using a tall battery and you have a very fat D-Tap plug they can interfere with each other.

Despite this the Core V-Mount battery adapter gets a big thumbs up from me. The voltage indication is most useful as is the ability to use a normal 4 pin 12v XLR feed.