Corrosion takes its toll even on the interior of the boat due to leaks, salt air and high humidity. When tested, most of these connections had high resistance. This is the proper method to splice wires. Ventilation Batteries develop heat when charging, as well as hydrogen gas. For that reason, the need to be in a well ventilated area.
Gel cells are particularly vulnerable to overheating damage.
Putting gel cells in covered, plastic boxes has proved to be a problem, and for this reason they are falling out of favor. Sometimes improved technology isn't an improvement after all. Why it is that there so many builders that install instruments, panels and switches in locations that are going to get wet is something I'll never understand. Oh, I know, you look at those switches and think that they're water proof. Well, you just go look at the back side of the panel and see if you still think so.