OMG You all are like a bunch of freakin' Kids. As I am trying to do research in this whole .com Every question, If answered at all, ends up in a pissin' match. How about some yes or no answers?
I worked Road Construction using Solar Powered Message Boards. They used 8 huge batteries and we always changed them out together for this very reason, but then during the winter, there is not enough sun in Indiana to keep them charged. We would have to swap them out every other week. After a couple of times being brought back to the shop to charge, they all looked alike and it was no longer an issue. They would last several years. Batteries charge and discharge all the time, it is what they do. Any parasitic amount from one age battery to another is so miniscule compared to the draw from a vehicle clock, or the memory of the car Computer Memory, or the dome lamp unless one of the batteries is total crap with a dead cell, and we all know what that can do. What a stupid thing to get in an argument about. Answer the question and stop trying to one up each other you are just a bunch of little girls. Even if you agree you argue about how much you agree! I must be getting to old for this crap!!!!!