[Al Skierkiewicz]

Ed,
I have been cautioned by the manufacturer and the Battery Institute that connecting two like batteries in parallel should pose no particular problems. Provided that the batteries are of the same age, type, and life (charge/discharge) history. However, with seven in parallel I would recommend steering diodes or switching of some sort. Depending on the current capability of the array, you might want to switch batteries for charging. i.e. have one on charge while the others are delivering load current. Most RV suppliers carry such diodes for RV dual battery systems. They use Schottky diodes for a lower forward voltage drop in most cases.
It would seem that the problem exists with circulating current between batteries of differing terminal voltage. As one battery sags, the other battery will try to deliver current until the terminal voltages are again equal. Unfortunately, this turns into a domino effect.
If size is a major concern, perhaps single cell batteries in series might better suit your needs. What is your application?