I am having a current problem with my solar, and I imagine a lot of you on solar will have this very same problem. What happens is this: My batteries go into bulk charge at about 14.6 for a couple of hours and then drop down into a float charge of about 13.4 for the rest of the day. As soon as the sun goes all the way down, the points start dropping as well. After talking to a couple of the so called experts I am no disconnecting about 6 of my batteries at a time, allowing them to sit for about 4 hours to level off and then testing them as six volt batteries. If no noticeable change then it will almost have to be a bad dioade in one of my panels. Anyone out there know how to check out dioads ? This one has me stumped so far.