You are probably thinking about the whole battery. But if you consider that it can be split into multiple modules, the weight of a module will not be that big.
Benefits of such design will be:
* lower operating weight since you wont need many modules for short trips
* lower registration weight of a vehicle
* the tires and road won't be damaged as much
* one can swap modules at gas stations instead of charging and waiting
* and the modules can be used as part of a house battery
In fact there is an european startup for microcars https://www.helixx.tech/ where they explore similar idea.
Benefits of such design will be: * lower operating weight since you wont need many modules for short trips * lower registration weight of a vehicle * the tires and road won't be damaged as much * one can swap modules at gas stations instead of charging and waiting * and the modules can be used as part of a house battery
In fact there is an european startup for microcars https://www.helixx.tech/ where they explore similar idea.