An AA, AAA, C, D, or 9V battery comprising: a housing; a positive terminal; and a negative terminal; wherein the housing contains: a power source; and a voltage regulation device that is operatively connected to the positive terminal, the negative terminal and the power source, wherein the battery has an output voltage and an output current between the positive terminal and the negative terminal in use, and further wherein the voltage regulation device includes: electronic components that are operatively connected to each other to regulate the output voltage to a programmed variable level; a current sensing circuit that is adapted to sense the output current or a current of the power source of the battery; a controller that is operatively connected to one or more of the electronic components of the voltage regulation device; a buck regulator configured to selectively provide the output voltage; and a linear regulator configured to selectively provide the output voltage, wherein when the output current or current of the power source is below a pre-determined threshold, the controller is configured to disable the buck regulator and enable the linear regulator, and when the output current is above the pre-determined threshold, the controller is configured to enable the buck regulator and disable the linear regulator. a housing; a positive terminal; and a negative terminal; wherein the housing contains: a power source; and a voltage regulation device that is operatively connected to the positive terminal, the negative terminal and the power source, a power source; and a voltage regulation device that is operatively connected to the positive terminal, the negative terminal and the power source, wherein the battery has an output voltage and an output current between the positive terminal and the negative terminal in use, and further wherein the voltage regulation device includes: electronic components that are operatively connected to each other to regulate the output voltage to a programmed variable level; a current sensing circuit that is adapted to sense the output current or a current of the power source of the battery; a controller that is operatively connected to one or more of the electronic components of the voltage regulation device; a buck regulator configured to selectively provide the output voltage; and a linear regulator configured to selectively provide the output voltage, electronic components that are operatively connected to each other to regulate the output voltage to a programmed variable level; a current sensing circuit that is adapted to sense the output current or a current of the power source of the battery; a controller that is operatively connected to one or more of the electronic components of the voltage regulation device; a buck regulator configured to selectively provide the output voltage; and a linear regulator configured to selectively provide the output voltage, wherein when the output current or current of the power source is below a pre-determined threshold, the controller is configured to disable the buck regulator and enable the linear regulator, and when the output current is above the pre-determined threshold, the controller is configured to enable the buck regulator and disable the linear regulator.