Battery draining fast and converter running hard

While at the service center and during investigation, they had on all the lights. Very common. Sence they where investigateg the 120 volt side, it was not hooked up to shore power. Lights are 12 volt, they will draw a battery down in short order if they are on for any length of time. All normal. Plug it ito shore power and leave it for a day or two. The convertor fan will run with more load, normal. It is functioning as designed.