Will our Gem charge itself all winter?

We drive a 2005 gem E2 with new gel batteries. We put it to bed for the winter and were wondering what we have to do to get it to charge itself every 14 days? Does it have to be in the off mode? We keep unplugging and replugging it, but the snow is building up and it would be easier if we could just leave it in the shed and not think about it.

Arlen Lemley told us about the winter charging feature, but we have forgotten if we had to have it in the off mode to have it happen.

Anyone know?