Yesterday before my ride woke up the pedals (v4.1) and received a warning on my watch that the battery levels were low. I didn't have any spare batteries so I did my ride.
2h 30mins into the ride the right pedal cut out and caused the power reading to be wrong and it also affected the performance condition which went down and had a knock-on effect on my VO2max and the Daily Suggest Workout for today.
I checked the sensors after the ride and it showed a sensor error of Left: 400 - 0 and no information on the right pedal.
I changed the batteries this morning:
R: 2.58v original , 3.24v new Duracell
L: 2.68v original, 3.25v new Duracell
Voltages measured open circuit/no load using a DVM.
The error cleared on installing fresh batteries. It seems that the minimum battery level is around 2.6v no load. Obviously all these voltages will drop slightly when the pedals are awake and power is being consumed by the electronics.
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I was disappointed that there was so little warning. I had expected to be warned when the lowest battery was within 10% or even 5% of the lowest acceptable voltage to the pedals, but not 2 or 3%. Given that the batteries last 100 hours or so, that would have been several days previously. After all previous activities the sensor display in Garmin Connect had shown the battery as being full/OK.
This could be a problem with particular types of batteries behaving differently but the batteries that failed were the original ones supplied by Garmin so that would be unusual if Garmin had done their low battery warning testing on different batteries that are supplied to customers.
In any case it would seem straightforward to adjust the warning voltage threshold to give a little more notice.
It would also be good to get some granularity of the charge state on GC instead of either good or bad.
