[USER=2979]@LBrandt[/USER]
Between the computers running in the background and the brake controller lights staying on, it definitely is running your battery down.
Being you don't drive it very often in the winter, get a battery maintainer with a desulfator like the BatteryMinder 1510. We have quite a few of these and use them on our vehicles and toys like the Polaris General and Honda Goldwing Trike.