Batteries don't normally have "fill marks" per se. The rule of thumb is water level should be 1/8" or more above the plates inside the battery...also, never use tap water to raise the level if they're low...use distilled water.
Yep,
1. electric
2. water
3. sewer
4. level
5. slides out
Then just the reverse when breaking camp.
Bill
When I'm all done when closing up, I turn off the engine and hit each slide one more time. I've found that when I raise the jacks one or more slides will creep out 1/2 to 1 inch. Not a big deal, but I like them nice and tight - especially when it's raining.