This present embodiment relates generally to the electrical treatment of malignant tumors and neoplasms by applying a voltage to affected tissue. Devices and various adaptations therein are described for use in electrical therapy. Additionally, various ambulatory devices are described which advantageously increase versatility of the electrical therapy system. The ambulatory devices may include an internal and external power source and/or a first and second power source. The ambulatory devices may also include communication means for communicating between various portions of the device.