A portable power supply device can include: a device housing； a controller； at least one battery in the device housing and operably connected to the controller； at least one electrical port operably connected to the at least one battery, the at least one electrical port being configured for providing electrical power from the at least one battery to an external electrically-powered device under control of the controller； and an extendable tray, which can be in an extended position in which the tray protrudes outwardly from the device housing, and a retracted position in which the tray is concealed within the device housing. A kit can include the device and a defibrillator. A method of charging an electronic device can be performed by plugging in the electronic device to one of the ports. A method of performing a medical procedure can be performed with the aid of portable power supply device.
