My garage is not heated and I left my bike without the trickle charger on it for a few weeks while we had snow/ice then had a problem starting it. The cold really kills off these lithium batteries. I kept it on the trickle charger since then. In the summer when I ride it more often I'll leave it off. If I leave it more than a couple weeks I'll put the charger back on it.everything electrical was totally dead
As with most manufacturers they calculate the minimum required size of battery and put those in the machines.