A method comprising: at an electronic device with one or more processors and memory: attributing a portion of battery usage of a first hardware subsystem during a first time period to a first application based on the battery usage of the first hardware subsystem that occurred during activity by the first application during the first time period; attributing a portion of the battery usage of the first hardware subsystem during the first time period to a second application based on the battery usage of the first hardware subsystem that occurred during activity by the second application during the first time period; receiving a request to display a battery usage user interface corresponding to the first time period; in response to the request to display a battery usage user interface corresponding to the first time period, displaying the battery usage user interface that includes a representation of the battery usage attributed to the first application during the first time period and a representation of the battery usage attributed to the second application during the first time period; attributing a portion of battery usage of the first hardware subsystem during a second time period to the first application based on the battery usage of the first hardware subsystem that occurred during activity by the first application during the second time period; attributing a portion of the battery usage of the first hardware subsystem during the second time period to the second application based on the battery usage of the first hardware subsystem that occurred during activity by the second application during the second time period; receiving a request to display the battery usage user interface corresponding to the second time period; and in response to the request to display the battery usage interface corresponding to the second time period, displaying the battery usage user interface including a representation of the battery usage attributed to the first application during the second time period and a representation of the battery usage attributed the second application during the second time period. attributing a portion of battery usage of a first hardware subsystem during a first time period to a first application based on the battery usage of the first hardware subsystem that occurred during activity by the first application during the first time period; attributing a portion of the battery usage of the first hardware subsystem during the first time period to a second application based on the battery usage of the first hardware subsystem that occurred during activity by the second application during the first time period; receiving a request to display a battery usage user interface corresponding to the first time period; in response to the request to display a battery usage user interface corresponding to the first time period, displaying the battery usage user interface that includes a representation of the battery usage attributed to the first application during the first time period and a representation of the battery usage attributed to the second application during the first time period; attributing a portion of battery usage of the first hardware subsystem during a second time period to the first application based on the battery usage of the first hardware subsystem that occurred during activity by the first application during the second time period; attributing a portion of the battery usage of the first hardware subsystem during the second time period to the second application based on the battery usage of the first hardware subsystem that occurred during activity by the second application during the second time period; receiving a request to display the battery usage user interface corresponding to the second time period; and in response to the request to display the battery usage interface corresponding to the second time period, displaying the battery usage user interface including a representation of the battery usage attributed to the first application during the second time period and a representation of the battery usage attributed the second application during the second time period.