Here's the URL for an automatic pressure equalization system based on using a leak detector to determine when more air is needed in a battery pod that I spoke of in my last below e mail. http://f1.grp.yahoofs.com/v1/YOD1Qfq2WApnnC2WtPa1MtQsX_tf6hYUPCssbbyBvGkB4oMxVxBv2Aq02vIGtJnGN8nYpBIB77bBJj8MPRWMeQQb5Yup59WylA/compensator.jpg And here's a schematic of the same thing..... http://f3.grp.yahoofs.com/v1/YOD1QWy0e5JnnC2WY4jllrpWynGSj_CMYjOLBagGSyX3PSL55mTgYLB-gmPwwggHxqn8bzTVCXk_JzfSL2L0Gj7NzpU72GxXew/compensator1.JPG