The CooPower sealed lead-acid rechargeable battery (VRLA battery) is leak-proof and maintenance free. The Superiority of VRLA battery is derived from its uniquely efficient oxygen recombination technology. The oxygen evolved from the positive plates diffuses through the micro porous glass fiber mat to the negative plates where it is changed back to water by recombination reaction, eliminating the need for water addition .The result is a maintenance free battery. 　 [ No Free Acid ] All of the electrolytes are absorbed into the positive plates, negative plates, and the micro porous glass fiber mat. There is no free acid inside the battery, therefore the VRLA battery can be mounted in any location. 　 [ Safe and Sealed ] The unique construction and sealing technology ensure that no electrolyte leakage can occur from the terminals or cases of any VRLA batteries. 　 [ Maintenance-Free Operation ] During the expected service life, there is no need to check the specific gravity of electrolyte or to add water. 　 [ No Corrosive Gas Generation ] There is no corrosive gas generation during normal usage, as gas generation during over-charge is recombined in an unique "oxygen cycle".