It doesn't need a connection during a session, just after so it can upload your data.
Re the power fluctuations, do you have power smoothing set to 3 seconds? If not the power figure will jump around a lot. BTW, the connection between my GSC-10 and Garmin dingle very occasionally drops out (maybe 3 times an hour) for a few seconds. How long does your power cut out for?
It doesn't need a connection during a session, just after so it can upload your data.
Re the power fluctuations, do you have power smoothing set to 3 seconds? If not the power figure will jump around a lot. BTW, the connection between my GSC-10 and Garmin dingle very occasionally drops out (maybe 3 times an hour) for a few seconds. How long does your power cut out for?