Provided are systems and methods for configuring battery packs in electric vehicles. A battery pack may include a plurality of battery modules, a support part, and at least one opening provided on the support part. The support part may be provided with a bottom for supporting the plurality of battery modules, sides, a top, and an accommodation space formed by the bottom, the sides, and the top for accommodating the plurality of battery modules. The opening provided on the bottom of the support part may enable the plurality of battery modules to be passed through the at least one opening and be detachably mounted to the bottom of the support part so as to be supported by the bottom.