NOVELTY - A high-efficiency lead acid battery with liquid electrolyte has a container component (12) in plastic material sub-divided internally into several cells (14) in which one or more negative plates or electrodes and one or more positive plates or electrodes are positioned, immersed in an electrolyte and delimited by porous separators, in which connection elements (40) are positioned between the electrodes and cells. The high-efficiency lead acid battery further has a cover (16) fitted with plugs which close the accesses to the cells and incorporating truncated cone terminals (18).    USE - High efficiency lead acid battery is used for stop and start cycle used in hybrid electric-type vehicles.    ADVANTAGE - The environmentally-friendly lead acid battery has excellent efficient recharging in recovering braking energy and in stop and start cycles with reduced power consumption, and economically provides hybrid electric-type vehicles having excellent reliability and durability.    DETAILED DESCRIPTION - A high-efficiency lead acid battery with liquid electrolyte comprises a container component in plastic material sub-divided internally into several cells in which one or more negative plates or electrodes and one or more positive plates or electrodes are positioned, immersed in an electrolyte and delimited by porous separators, in which connection elements are positioned between the electrodes and cells. The high-efficiency lead acid battery further has a cover which closes to hermetically seal the container component, and fitted with plugs which close the accesses to the cells and incorporating truncated cone terminals. The separators are formed of two overlaid layers in which the primary of outermost layer is in relation to the positive electrode and made of polyethylene, and secondary of innermost layer contains non woven polyester and has a thickness of 0.1-1 mu m at 5 kPa. The containment layer of each negative plate or electrode contains stratified, polyester-based non woven in an amount of 60% or more.    DESCRIPTION OF DRAWING(S) - The drawing shows a cross-sectional view of high-efficiency lead acid battery.    Container component (12)    Cells (14)    Cover (16)    Truncated cone terminals (18)    Connection elements (40)