I just did a routine maintenance on my battery Motorcraft stock replacement battery.
I pulled the battery, put it on a flat table and pulled the fill caps.
After reading in all three manuals and watching multiple youtube vids, everyone kept saying "fill to level of the split rings." I didn't see any split rings. Then, one one of the youtube vids featuring someone at least dressed as a tech it said "fill to the bottom of the fill tubes" which is what I did. I brought the fluid level up to where the top of the fluid was just touching or a hair below the bottom of the fill tube for each cell.
Is that the correct fill level or did I fill it too much?

I used distilled water.

 

First off, I thought all the car battery now are maintain free and you couldn’t even add water to them?

Back in the days when you would remove the plastic caps to check the fluid level you would add it as you said. So I think you did it correctly.

But if the battery was low or discharged, you would only add water to cover the plates because the level would come up as it was left on the battery charger. After it is fully charged you would service it to the normal level.

Bottom line, the plates must be covered in water.
If the level is a little high it will boil off during charging. If you think the battery level is a little high, leave the battery charger on the battery over night or just go have a beer and forget about it, as it will come down eventually.

Jim

 

The battery was fine and fully charged when I topped it off. It seems today the two types of batteries commonly available are "maintenance free" and "nearly maintenance free." The first one is the type with the built in hydrometer -- that little window which should show green -- and no caps. The second is what I have and which is still quite common which has removable caps and no "window." Mine took about 10 oz of water and it's a one year old battery.

 

If one cell had very low water/acid level, below the plates, you have a problem.

If the cells all had water above the plates it would be normal.

 

You'll know if you overfilled it. It will run out the top and down the side of the battery and make a real mess that you have to clean up after it's been charging for awhile.