I'm fed up, I really can't stand this issue any longer! Firmware 12.50 had been a nightmare and after months they finally fixed it. How can it be that after a couple of updates the same problem comes back even worse than before! Usually I ride for 5-6 hours and now I receive the low-battery alert each and everytime. This is really embarassing.
The latest ride I had having a few waiting and coffee break. Which was close to 5 hours in total. The temperature was above zero degree Celsius. By the time I arrived home, the battery had less than 10% left.
My last ride was 4.15h, battery went from 100% to 6%, but I left the 520 turned on at home and it was recording for 4.30h more... It seems that the % is not calculated properly.
I have the same suspicion about a significant non-linearity in the battery's state-of-charge profile. My Edge 520 can lose 10% whilst I'm getting ready to ride! But then I've observed it sit at 24% for approx 15 minutes.
I'm not sure if the SoC was corrupted by an update and doesn't have the ability to relearn the 0 and 100% points, or whether my battery is just dying.
Updated to 12.90, left running until battery is completely drained, I had to turn on the 520 3 or 4 times until battery was dead. Now I am testing it, I left it again at home running alone, no bt connected, more than 13 hours and 3% left, later I will try to check the fit file to see if the draining was linear or not.
Only the first half of the battery has a linear draining, since 5% the battery lasts forever... it is still recording now (+1 hour) with 0% of battery... It was configurated with smart recording, I will try with 1 second. Despite this, after calibration it looks a much better than before. Also I think that low temperatures affect a lot this battery, battery drain changes a lot comparing winter (4-5ºC) and summer (30ºC).
