Stackable battery assemblies and methods of use are disclosed herein. An example battery assembly includes an energy storage device, a housing having a locking unit, a receiver unit, and a sidewall that are interconnected to form an enclosure that retains the energy storage device. The locking unit can include a plate that is spaced apart from the sidewall of the housing by a second sidewall, the plate supporting a first electrical connector that is electrically coupled to the energy storage device via a locking member. The receiver unit can include a third sidewall that defines a cavity that is shaped to correspond with the locking unit, the third sidewall having a lock notch and a second electrical connector that is electrically coupled to the energy storage device.