Central degassing - when does it bang

Battery suppliers have answered the demands of their customers for less ventilation for equipment cabinets where batteries are included with solutions for central degassing on the VRLA-Batteries. From several intelec´s we have reports that the majority of hydrogen and oxygen produced by VRLA-Batteries is lost through the case walls instead through the vents. Quantities are rarely reported and difficult to calculate The scope of this paper is to show how much hydrogen is escaping through the container wall of VRLA batteries with central degassing as an option and when the concentration of hydrogen will reach an explosive level.