Wade,
After my previous battery expired, I installed an AGM, or absorbed glass mat, battery. This kind of battery does not require any ventilation as the gases are reabsorbed by the battery.
AGM batteries have other unique features. Since the sulfuric acid in these batteries are absorbed in glass mat, they do not contain any liquid. They therefore are spill-proof, may be mounted in any position and do not require electrolyte level checks. I like this latter feature a lot as the battery box in my 3124KS is located in a well at the bottom of a cabinet, and, it is an arduous tasks to get the battery out for an electrolyte check. The primary disadvantage of AGM batteries is that they cost twice as much as conventional lead acid batteries. They may last 1-1/2 to 2 times as long as the latter type, however, so that AGM batteries may be a good value after all. :
