Hi Paul
Adding to Jeff’s comment regarding powering all of this.
The supply on board a ship could be anything.
DC, 24V, 110V etc
AC 24V, 110V, 240V, a mixture or very important 50/60Hz or (a trap for the unwary) 400Hz.
We must assume you know exactly what is on board in the way of supply voltages and are making suitable provisions. These days there might even be dedicated 5V DC outlets.
Whatever, the last time I had anything to do with anything on a ship you MUST NOT use any starting batteries. They must be exclusively for starting the engines. That is if electric starting is used.
Cheers Bob
