Battery compartment assembly

I am just completing the assembly of our rov. How are the end caps on the battery compartment secured. I don’t see any reference in the assembly instruction.
I also noticed another question on the forum re: securing the battery in the compartment, but didn’t see answer

The battery enclosure endcaps are not secured in the current revision of the BlueROV2. This has not posed an issue for us, the water pressure will keep them in place. The battery does not generate much heat, so the pressure inside won’t increase to the point that the endcaps will come off after it has been sealed, even in air.


They are just pressure fit, there is no physical retainer.

We have used a bungee cord around both ends to ensure it does not pop open.

Thanks for the response. I had another basic question. I wanted to confirm
the wiring of the ethernet RJ45 connector on the tether.

I had crimped a connector, blue wire to pin number 4, white wire to pin
number 5. Is this correct. I am not familiar with the Pixhawk and wanted to


Charles E. Callaway, P.E.


Callaway Marine Technologies Inc.

2765 Vista Parkway Suite H4

West Palm Beach Fl 33411

Tel: 561-471-1771

Cell: 954-415-8722

Fax: 561-471-1793


Hi Charles,

I’m confused by your question. Do you have a BlueROV2 kit, or are you building a custom ROV?

  • We don’t suggest or require crimping RJ45 connectors in any of our products (It is possible to use our products this way, though).
  • The Pixhawk does not have an RJ45 receptacle (the Raspberry Pi does).
  • In our advanced electronics package, the blue and white tether wires are terminated at the screw terminal blocks of the Fathom-X interface board. The remaining 6 conductors in the tether are unused. With the standard electronics option, Ethernet communications are not used.
  • Crimping an RJ45 connector for standard Ethernet communications requires terminating 4 conductors in the connector. These are the orange and green pairs by convention.


The termination of the blue and white tether wires with the advanced electronics package can be seen here.

I’m referring to the other end of the tether. What’s the connection on the topside end of the tether. I thought it went into an Ethernet/ USB connector.


The other end of the tether connects to a Fathom X in the same way, then an Ethernet cable connects to the Fathom-X.

The components are connected in this manner:
Pixhawk <-> USB cable <-> Raspberry Pi <-> Etherent Cable <-> Fathom X <-> Blue Twisted Pair <-> Fathom X <-> Ethernet Cable <-> Ethernet jack on your computer or usb/ethernet coverter.

I see. I had thought the tether had to go into the Ethernet connector. I see what you mean.