Did I damage my house batteries?

pianotuna wrote:
Don't fill an uncharged battery much over the plates.

Fully charge, and then add distilled water.

Then do a short "stirring charge".

exactly. Almost a direct quote from trojan Flooded cell batteries water level is highest once fully charged. if you fill when partially or near fully discharged water level can end up being way to high once charged.

As your charging your increasing the concentration of sulphuric acid in the cells. that increases cell water volume.

Just make sure the plates are covered slightly before you charge. then check for proper water level and add water if needed once the battery reaches full charge.