Battery box

A battery box, comprising:

• a lower box body, wherein the lower box body comprises:
• a first plate, comprising:
• a bottom wall;
• a peripheral wall, which is connected to a periphery of the bottom wall and extends upward;
• and the bottom wall and the peripheral wall form an accommodating space opening upwards;
• a second plate, which is fixed to the bottom wall from a bottom and engages with the bottom wall to form a flow passage, wherein the second plate is provided with:
• at least one protrusion, which protrudes from a side facing at least one reinforcing beam to the first plate and extends along a transverse direction;
• and at least one opening, which runs through the at least one protrusion of the second plate along a height direction and extends along the transverse direction, the at least one protrusion of the second plate being connected to the bottom wall of the first plate in a sealed manner;
• and
• the battery box also comprises:
• the at least one reinforcing beam, which is arranged under the second plate and extends along the transverse direction, the at least one reinforcing beam being installed at a position corresponding to the at least one opening and being fixedly connected to the first plate and/or the second plate.