My 2nd helmet carries a 10R I think that is a different battery since its remote - battery was amazing for about the first year - and then really dropped quickly...
I ride with a USB cable handy and just ride with my helmet plugged in - kind of a pain,,
I noticed in cold weather <10'C it would die from full charge in 1-2hrs.... what I did to help this greatly was moved the battery to the inside of the helmet (dirt helmet lots of extra room) - it stays much warmer and works at least double that inside the warmth,,
The dropping issue not sure whats up there - I would recommend only using #1 for headset - I tried #2 for the headset and had a bunch of issue - now I leave it on #1 and all is good - rock solid actually on either of my headsets - 20s or 10r - connection to bike is not an issue...
I've had my 20S for about a year - and that thing is incredibly better regardless of temp - I seem to get 12-15hrs no matter if I'm using intercom radio or just mp3s from the phone...crazy good bat life...