Victron BMV-712 UTP cable

Kevin, it's an RJ12.

Kevin, I believe so but not 100% sure.

As Racey has identified, any standard RJ12 patch lead will work. RJ12 has 6 pins connected.
RJ45 has 8 and RJ11 has 4.
Just be aware that some retailers don't know what a standard RJ12 cable is.
I purchased one and had to return it as it was a "cross-over" cable.

Just check that the pins have the same colour wire connected to the corresponding pin at each end.
i.e. a straight through cable, pin1 to pin1, etc.