Low-maintenance lead-acid storage battery cover with large backflow space exhaust structure

The utility model discloses a low-maintenance lead-acid storage battery cover with a large backflow space exhaust structure. The cover comprises a large cover body and a cover plate, a row of exhaustbackflow holes are formed in the large cover body, the large cover body is provided with an opposite inclined face inclining upwards with the exhaust backflow holes as the center, the included angle between the opposite inclined face and the horizontal plane is 9 degrees, an acid blocking plate is arranged around each exhaust backflow hole, and each acid blocking plate is provided with a notch foracid liquid to flow in. A labyrinth retaining wall for guiding acid liquor to flow back is arranged between the exhaust backflow hole and the external exhaust hole and inclines towards the exhaust backflow hole. The large cover is provided with the opposite inclined surface which inclines upwards by taking the exhaust backflow hole as the center, so that the collection of acid liquor is facilitated, and the backflow speed