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Edge 530 power average problem

DanielBrodshaug

Is there some bugs in how Edge calculates power average?

Did a ride yesterday with following data in GC. 

Moving time = elapsed time = 13h50min = 49800sec

Total work = 8837kJ

Power average in GC = 192W

Calculated power average = 8837000/49800 = 177W (which is the same I get if I analyze the fit-file in DCrainmaker analyzer tool)

5154046592.zip

  • 0

    Have you disabled by any chance "Include Zero values" for your Power Meter?

  • 0 in reply to IceLed

    Include zeroe values is enabled.

    Difference between calculated and reported power average is about 8%.

    There is about 2h30min of zeros which is allmost 20% of elapsed time, so there has to be something else.

  • 0 in reply to DanielBrodshaug

    The values do reflect that zeros are being excluded.

    Looking in the file the training settings record shows that zero values should have been included.

    Try toggling the value on the Edge to force the value to be re-set.

  • 0 in reply to aweatherall

    I see what the issue is.

    The Edge is including zeros in the average power calculation. The issue is the difference between zero power and no power.

    Your workout has a number of reset periods that are long enough for the power meter to shutdown. When it shuts down it is no longer transmitting a power value of zero. The Edge is receiving no data in this period. No data is not the same as receiving a value of zero. Records that have no power data are excluded from the calculation as the Edge does not know what these values should be.Hence it looks like it is exclude zero values, but in fact it is excluding records with no values.

    Here is a section of the power data where you stop.The power meter sends zero power values until it shuts down. The NA values are the period of time in this sample where no power is received.

  • 0 in reply to aweatherall

    Thanks, this makes perfect sense!

    This was a vEveresting event, so there are 10 brakes without pedaling which probably made the PM fall asleep after a while.

    FWIW, seems like GC power curve include NA-values as zeros.

    GC power curve 5h = DCR analyzer power curve 5h = 209W

  • 0 in reply to DanielBrodshaug

    In think it is fine for post activity processing to decide to replace missing values as zero. I think as a recording device the Edge just needs to capture what it is getting.

    If you do a similar event again you can write a connect IQ data filed that takes the total work and divides by the elapsed time.

    This app should allow you to plug those values in quite easily.

    https://apps.garmin.com/en-US/apps/394941a6-4e73-4843-820b-fdcfbc877f3a#0