Sealed FLA batteries and venting

It would take an uncommon meeting of high temperature, sustained high voltage, and a long period of time to cause a VRB or calcium/calcium flooded battery to vent gas enough where it would become any sort of issue. I have seen malfunctions of 15.0+ volts applied for longer than a week and no -significant- expelling of gas occurred. I have an AGM stuffed under my bed and I feel secure with mere monitoring of voltage. Quite often a malfunction will be detected soon after it occurs. Manufacturers must take the safe route and insist that a vent system be incorporated. An upside down plastic pan with 1/4" hose heading to an outside exit will vent hydrogen very efficiently. Hydrogen rises aggressively and will take an exit tube.

Good old-fashioned common sense works wonders. There is no need to abandon plans to incorporate VRB batteries indoors or within a confined space. A quarter-inch tube is quite unobtrusive.