Power data different between edge 520 and fenix 5

Former Member over 6 years ago

Hello all,

I have been using a fenix 5 for a while coupled with my power2max NG eco power meter, and I purchased yesterday an Edge 520 head unit.

I am surprised of my power results uploaded from both devices to GC or Training Peaks : there are important differences between power data between the F5 and the edge 520 : average and normalized power are about 15% different between the 2 devices.
I have isolated a short effort to illustrate the differences. No coasting, no zero power output, and thus the differences below:
F5 avg power = 238W
Edge 520 avg power = 223W
F5 normalized power = 277W
Edge 520 normalized power = 237W

See the pictures attached.

Both devices are in smart recording modes, excluding zeros.

Could anyone help me understand the origin of the problem and identify who tells the truth?

Thank you very much

Quentin

0 hansap over 6 years ago

I have seen significant differences between my Edge 520 and my Fenix 5 with my Vector 3 pedals. I have concluded that the sketchy RF performance of the F5 is the most likely culprit. The Fenix 5 is known to drop sensors more frequently than any other Garmin device. I can only assume that Garmin compensates for that by extrapolating values in the Fenix 5 until the connection with the sensor can be re-established. Garmin designed and released the Fenix 5 plus to deal with the RF problems. I would say trust the Edge 520.

0 mcalista over 6 years ago

The most obvious thing about those graphs is the dramatic difference between in how "noisy" the data is. The smart recording on the F5 is applying a large amount of smoothing.

I'd suggest a new comparison with 1s recording on both units.

The other thing is to check whether both are connecting as an ANT+ sensor, or whether the F5 is in fact picking up the PM as BLE.

0 Former Member over 6 years ago

Thank for the feedbacks.

Do you recommend using ant or Bluetooth?

I will check and apply the 1 sec recording mode.

0 SUSSAMB over 6 years ago

Please post any further help here https://forums.garmin.com/forum/into-sports/cycling/edge-520-aa/1457604-power-data-différent-between-edge-520-and-fenix-5