US Patent 9728013 Engine detection

Various implementations described herein are directed to a non-transitory computer readable medium having stored thereon computer-executable instructions which, when executed by a computer, may cause the computer to detect electrical noise corresponding to one or more engines starting or running. The computer may record a first timestamp corresponding to the engines starting or running. The computer may detect that the engines have stopped. The computer may record a second timestamp corresponding to the engines stopping. The computer may also use the first and second timestamps to determine engine runtimes.