Emergency generator??

When you had a bunch of halogens on 24v dc circuits, they would dim and brighten on their own as the battery charger goes through various modes of charging, or other dc loads kick on, that's why they used a transformer so the lights stayed on at an even brightness. A lot of yacht manufacturers do this.

How does a transformer work on 24VDC lights? Must have missed that class when working on my EE.

Woops meant 24v ac lights instead of dc lights.

But ACv lights don't need a battery charger?

ACv halogen lamps will blink, even thru those lil hatteras transformers when some Air units cycle on or DCv halogens change while on charger or mains alternators.

Our fix, Replace the ACv transformers with ACv to DCv power supplies and run DCv LED lamps.
These power supplies or drivers keep the LEDs at a constant level and still use very little current.

12v LED have better dimming qualities than 24v LED. Also, best to still run the dc power through a transformer designed for the LED bulbs by the manufacturer. Third party dimmers , like those made by Blue Sea, don't provide quality dimming control. At low setting the darn things flicker. There's actually a science here that needs to be followed...

The boat has combination of dimmers.the guest rooms had small dimmers modules called I-something that were not working with LEds We just removed them as nobody was using them anyway and rewired the boxes. The master and all other areas have an older Lutron system which works fine with LEDs.

it s always a bit hit or miss.

problem with an 24 VAC system is that you need compatible bulbs which are harder to find. When I replaced the antique halogen stern floodlights I had to use DC - AC converters for the Lumitec fixtures to work