Battery pack of electric vehicle, electric vehicle chassis and method for replacing battery modules

A method for replacing a battery module in an electric vehicle, the method comprising:

• identifying a first battery module from among a plurality of battery modules in a battery pack, wherein the battery pack is located within the electric vehicle and comprises:
• the plurality of battery modules;
• a support part for supporting the plurality of battery modules, wherein at least one opening provided on either a bottom or a side of the support part such that at least one of the plurality battery modules can pass through the at least one opening and be detachably mounted to either the bottom or the side of the support part;
• a layer mounted above the top of the support part to cover the plurality of battery modules;
• and
• a protector sheet mounted below the bottom of the support part to cover the plurality of battery modules;
• detaching the first battery module from the bottom of the support part;
• removing the first battery module from the support part by passing the first battery module through the at least one opening;
• inserting a second battery module into the support part by passing the second battery module through the at least one opening;
• and
• mounting the second battery module to the bottom of the support part.