A battery assembly, comprising: a battery module, comprising a battery array, which comprises at least two batteries arranged side by side along a first direction (y), wherein an vent is provided on an end cover of the battery, the end covers of all the batteries in the battery module have the same orientation, and the battery module has a first outer surface and a second outer surface opposite to each other along a second direction (z) that is perpendicular to the first direction (y); and a protection member, being configured to protect against a flame sprayed via the vent, and comprising a first protection section, a second protection section, and a third protection section, wherein the second protection section and the third protection section are respectively connected to two opposite ends of the first protection section along the second direction (z), and the second protection section and the third protection section are both bent in a direction closer to the battery module relative to the first protection section; wherein the first protection section covers all the vents of batteries in the battery assembly, a part of the second protection section is covered on the first outer surface, and the third protection section abuts against the end cover of the battery corresponding to the second outer surface; the first protection section comprises a first portion and a second portion connected to the first portion, the first portion is connected to the second protection section, the second portion is connected to the third protection section, and the first portion and the second portion are separated and at least partially overlapped in a third direction (x) that is perpendicular to the first direction (y) and the second direction (z). a battery module, comprising a battery array, which comprises at least two batteries arranged side by side along a first direction (y), wherein an vent is provided on an end cover of the battery, the end covers of all the batteries in the battery module have the same orientation, and the battery module has a first outer surface and a second outer surface opposite to each other along a second direction (z) that is perpendicular to the first direction (y); and a protection member, being configured to protect against a flame sprayed via the vent, and comprising a first protection section, a second protection section, and a third protection section, wherein the second protection section and the third protection section are respectively connected to two opposite ends of the first protection section along the second direction (z), and the second protection section and the third protection section are both bent in a direction closer to the battery module relative to the first protection section; wherein the first protection section covers all the vents of batteries in the battery assembly, a part of the second protection section is covered on the first outer surface, and the third protection section abuts against the end cover of the battery corresponding to the second outer surface; the first protection section comprises a first portion and a second portion connected to the first portion, the first portion is connected to the second protection section, the second portion is connected to the third protection section, and the first portion and the second portion are separated and at least partially overlapped in a third direction (x) that is perpendicular to the first direction (y) and the second direction (z).