A liquid-absorbent composition, which has a liquid-absorbent crosslinked resin that exhibits excellent absorption of the nonaqueous electrolyte of nonaqueous electrolyte secondary cells that constitute a nonaqueous electrolyte battery pack (and particularly a lithium ion nonaqueous electrolyte rechargeable battery pack), contains a powder of a liquid-absorbent crosslinked resin produced by crosslinking a methyl vinyl ether/maleic anhydride copolymer with a polyfunctional isocyanate compound, and a binder resin. Also, a liquid-absorbent sheet for a nonaqueous electrolyte battery pack contains supporting substrate and formed on one side of a supporting substrate a liquid-absorbent crosslinked resin layer, produced by crosslinking a methyl vinyl ether/maleic anhydride copolymer with a polyfunctional isocyanate compound. The nonaqueous electrolyte battery pack contains a battery case and disposed within the battery pack a nonaqueous electrolyte battery cell, a wiring circuit board, and an electrolyte absorption member formed from the liquid-absorbent sheet for absorbing electrolyte in the event that electrolyte leaks from the nonaqueous electrolyte battery cell.