Coach batteries, replacement. UP DATE

Have to agree, if you don't boondock 6 volt batteries are unnecessary, 12 volt will do you well. If you only have only 2 batteries for your coach, in the long run 12 volt batteries are also better from the standpoint that if one 6 volt fails you loose certain functions in your coach until replaced. Interstate batteries are fine, but keep in mind that they are built by others for Interstate. The last I heard by at least 2 different manufacturers there may be more. Napa brand batteries were at one time built by the same manufacturers, don't know if that is still true or not. Battery brands change manufacturers all the time, most changes are based more on cost than on quality.