Originally Posted by
Polaris OBark
I don't think it is an issue. It never has been for AXS (a year) or Di2 (10 years) in my unheated, detached garage. The garage interior probably never goes below freezing. If it is a problem, you could bring the bike, or just the battery, into your house.
After I posted this, I took the mountain bike out for a ride. The battery was in the green zone while in the (cold) garage. Five miles later, it was kicking a 20% low charge warning to my Garmin.