A vented-type leak-resistant motor cycle battery comprising a housing in which a plurality of cells are mounted, a battery cover sealed to an upper end of the housing in a liquid tight manner so that the battery cover overlies the cells each having a vent chamber, a filling hole and a filling plug and a vent chamber cover sealed to the battery cover in a liquid tight manner, the battery cover being provided with a vent line extending in a longitudinal direction of the battery cover in flow communication with the spaces above the cells and having an exit end tilted upwardly toward the outside and a vent cap assembly being fitted to the vent line at the tilted exit end.