BATTERY HOLDER, POWER TRANSFER DEVICE, ELECTRIC VEHICLE AND INSTALLATION METHOD FOR POWER TRANSFER DEVICE

Provided are a battery holder, a power transfer device, an electric vehicle and an installation method for electric vehicle. The battery holder includes a fixing bracket, the fixing bracket has an upper-position accommodation cavity, an upper-position sensor is arranged in the upper-position accommodation cavity, the upper-position sensor is used for detecting the supporting portion of the battery pack, so as to determine whether the battery pack has been installed in place relative to the battery holder in the height direction of the electric vehicle; and/or, the fixing bracket has a front-position accommodation cavity, a front-position sensor is arranged in the front-position accommodation cavity, the front-position sensor is used to detect the supporting portion of the battery pack, so as to determine whether the battery pack is installed in place relative to the battery holder in the length direction of the electric vehicle.