First question is it electric or gas. I’m assuming electric since you said batteries.
Next question is the year if in the 2000’s then your charger is setup to start automatically every 15 days as long as you don’t have a power outage. If that happens then you need to unplug everything to reset it.
Batteries love cold weather so that’s a good thing. Your cart more then likely has a run/tow switch. Make sure it’s in tow when not in use. Run will have a parasitic draw. If you don’t disconnect the batteries make sure you charge them after every use then after a couple of week of non use.