NOVELTY - The package (10) has an inner container (20) to accept a battery (11) and formed by an inner-container surrounding wall (21) including an inner-container top wall, which forms an inner-container closure of an inner-container access opening. A fluid-impermeable intermediate container (30) seals the inner container. An outer container (40) encloses the intermediate container, and is formed by an outer-container surrounding wall including an outer-container top wall forming an outer-container closure of an outer-container access opening. An innermost container seals the battery.    USE - Protective leak-proof package for safe transportation of a defective battery i.e. wet battery, in vehicles, utility systems, unINterruptible power systems and industrial machineries.    ADVANTAGE - The package is simple in assembly and safe in transportation in an improved manner. The package eliminates possibility for an erroneous assembly to avoid improper packaging of damaged or leaking batteries. The package allows easy access to the packaged batteries for inspection during transportation. The package allows re-closing free of additional supplies. The inner-container surrounding wall is free of three-way-corner sidewall junctions with the inner-container top wall and with an inner-container bottom wall, thus minimizing puncturing of an intermediate plastic bag, which envelopes the inner container. The package allows an inner spacer for positioning over the battery to limit battery movement.    DETAILED DESCRIPTION - The intermediate container is a plastic bag. The inner container is made of a cushioning material and an absorbent material. The outer container is made of a stiff material and a corrugated cardboard. An INDEPENDENT CLAIM is also included for a method for packaging a battery containing corrosive liquid.    DESCRIPTION OF DRAWING(S) - The drawing shows an exploded perspective view of a leak-proof packaging.    Protective leak-proof package (10)    Battery (11)    Inner container (20)    Inner-container surrounding wall (21)    Fluid-impermeable intermediate container (30)    Outer container (40)