Since I retired, the majority of my drives are fairly short. As a result, I try to remember to put my trickle charger on to ensure the battery stays topped up if I'm not planning on going anywhere for awhile.
I've never had a really definitive discussion about the charge logic on the GT. I know it shows on the instrument gauge primarily only when braking, but set on cruise on the interstate for hours, it must need to charge the battery at least sometimes...just not sure how and when it decides to do that. I will say that even with a new (last month) battery, the charger I have shows 25%, but quickly goes to 100% after less than 15-minutes or so, so it's not deeply discharged. Maybe it's a function of the charge point being in the engine bay, but the battery is 15-ft of wire away.