bulb 30 on each side of openings 30a at the base of the light bulb separated by insulating plastic post 123 in grooves 123a fig7 shows an enlarged one half in actual proportion cross sectional segment of the lens 14 the focal point 140 fp is determined by a lens equation in relationship to the optically clear plastic or glass material used the thickness between curved wall 142 relative to the cylindrical interior chamber wall 140 to project a 1 u00b0 beam of light on either side of center line cl circumferentially in a plane of the center line 360 u00b0 around the lens as emanating from the focal point 140 fp in addition an upper cone of light is projected that may be 6 u00b0 that goes through the dome 144 emanating from the focal point perpendicular to the center line plane thus the lens 14 projects a very concentrated beam in a narrow plane perpendicular to the vertical axis for 360 u00b0 around the lens and in a vertical narrow cone above the lens by improving the efficiency of the battery without increasing size or weight and especially by restricting the escape of gas bubbles per unit time and by enhancing sludge flow through aperture size in the battery housing in conjunction with a lens design to.