I have had an Edge 520 for a couple of years, and all has been fine, but last year, I bought a spare as I was doing an 'Everesting' and wanted a fail safe that I wouldn't lose data due to a failure.
Ive never used the back up one, but have just installed the Exert app to use on it, my problem is, for some reason, for this Edge to connect to my iphone, I must have the Garmin connect app running, and if I close the app, then the phone and Edge disconnect, has anybody any idea why? the original Edge 520 just connects when I turn it on?