Hi, there is the possibility that my battery monitor won't read exactly the same as my Fluke meter. Without a load on the system,
I don't believe that there would, could, should, or will be any difference in the 12 volt
reading at the battery or any other place on my trailer. To be actually different there has to be a load, short, poor hot, or poor ground connection. Your 12 Volt
battery/ies aren't trying to start an engine. There is no major load on your 12 Volt
system in your trailer.