All I know is what Wesmar tells me - they spec a 10A/24V circuit. The manual only shows power rating for the display which is not anywhere near that draw, but there are other 24v connections for gyro and actuators. Obviously, someome at Wesmar designed the system and knows this information, but that person is currently behind the curtain. Odd - my experience is that specialty manufacturers bend over backwards to assist Not Wesmar.
Wesmar states they only make 24v systems these days - they used to make 12v controllers but made design changes several years ago that necessitated going with 24v. My guess is fewer boats that install Stabilizers have 12v. As mentioned, Naiad also uses 24v but for 12v boats, provides a 12v to 24v converter. Some internet sleuthing indicates these converters are often used go power avionic systems in small aircraft and helicopters, so presumably they are reliable. But they need to be sized properly.
Wesmar's position is I got what I paid for and I need to figure out how to provide 24V/10A. They provided a hand written sketch on scratch paper describing addition of two batteries in series with 24v charger. When I asked about power draw, I got the vague answer of "we recommend a 10A circuit at 24V."
Very disappointed in what I thought was a quality company.