You are not working in automotive? mA is a considerable amount even when running. In switched off mode, any ECU (with very few exceptions) should not draw more

You are not working in automotive? mA is a considerable amount even when running. In switched off mode, any ECU (with very few exceptions) should not draw more than 100 nA. Remember, there is not only 1 ECU. There are around 40 to more than 100 ECUs. A battery should deplete not more than 50% in 8 weeks.