I think I've been able to okie-engineer a power solution for the P4K while on a Crane 3.
I posted this, w/ pictures on Facebook, if you care to see.
Since I'm not allowed to post a link in this forum...
You'll have to find the Blackmagic Pocket Cinema Camera 6K & 4K User Group, and do a keyword search for "okie", or "Brent Berry".
The hard part is finding the correct plug that will fit the Crane's 8v outlet.
The plug I used came from a mini DirecTV tuner power supply.
I'll get the measurements and formal nomenclature later.
The important part is that this plug has a pin in the center of the barrel that goes into a receptacle in the Crane's power socket.
Not an easy plug to find.
So, I cut off a length of the plug & cable, and solder spliced it onto the cable of a LP-E6 dummy battery.
The total cable length is now appox. 5".
Camera powers up without a problem.
I'll test it for Crane battery longevity and reliability with focus & zoom motors, SSD, XLR mic w/ phantom power, recording at 4k 60p.
I'll be putting it through the paces.
I'm preparing for an upcoming Israel trip, so trust me...I'll be thorough!
Stay tuned for my findings.
Before splicing, I performed a couple tests...First, I connected a volt meter to the ends of the bare wires while plugged into the 8v outlet.
This verified the positive and negative wires, and that I was getting the full 8v.
8.2v, actually.
Check! Then I tested the outlet while connected to the P4K's 12v power inlet.
While using the camera's 12v inlet, it will send a charge to the internal battery port.
So, I made sure it was empty. I also unplugged the SSD and anything else that might draw a current.
The camera powered up, but the battery level indicator on the screen was red, and showed 8v.
This would be my preferred power solution.
It would more closely resemble my typical V-mount rig where I have an LP-E6 battery in the camera as a backup, and uninterrupted power, while main power comes from the V-mount.
But the red indicator doesn't give me the warm & fuzzies, so I aborted that solution.
If there is a manufactured 3rd party solution like this, already on the market, I can't find it.
Maybe we can get IndiePro, Tilta, or PortKeys to come up with something.