Join Date: Oct 2007
My Motorhome: Swift Kontiki 615
Thanked 693 Times in 614 Posts
I have had a copy of that for years and it is a part of my Bible for the MH......
I will never allow ours to drop below 12.5v as like others I am concerned that some damage may be initiated.
I believe that if you have "cheap" batteries they are more susceptible to damage at lower voltage as the surface of the plates is less stable.
It does depend on the exact type of battery, but to me, err on the side of safety and the battery bank is likely to last longer......