Wet Maintenance free batteries are designed with Lead and Calcium alloy in the positive and negative plate chemistry or formulation.A more functional and effective design than traditional batteries with removable vent caps.Sealed batteries of this design have longer water retention and are a far more robust battery for today’s climates and conditions.Other benefits are:Less preventive maintenance due to less water lossMore forgiving when accidentally overchargedReduced terminal corrosion and ventilationLower discharge rateLess risk to users due to it’s maintenance-free construction