Abstract: An integral battery temperature control system monitors and heats a battery to enable operation in cold environments and utilizes a heating device coupled to one of the terminals of the battery to heat the terminal and thereby heat the electrode coupled thereto. The heated electrode is within the battery housing and internally heats the battery. A temperature sensor measures the temperature of the opposing terminal and a controller will terminate heating when the measured temperature of the opposing terminal rises above an upper threshold temperature value. The heating device be coupled with or be part of a discharge circuit, wherein electrical current from the battery is used to heat the battery. A discharge circuit is part of a battery unit monitoring module that balances the voltage of a plurality of battery units. The heating device may include a resistor or a transistor of the discharge circuit.