Included are embodiments of an ambulatory infusion device. Some embodiments include an energy storage for storing electrical energy utilized for powering the ambulatory infusion device. The energy storage may serve as a primary power source of the ambulatory infusion device. Also included is a dosing unit with an electrically powered actuator and an electronic controller, where the electronic controller controls operation of the electrically powered actuator. Some embodiments also include a testing unit for testing the energy storage. The testing unit may be configured to repeatedly carry out a test during operation of the ambulatory infusion device. Additionally, the test may include determining a control variable, the control variable being indicative of a capability of the energy storage for further powering the ambulatory infusion device.