Winter Storage for XB 500

I've finally put my XB 500 up for the winter. I removed the battery and stored it in my basement. Is it counter productive to the life of the battery if you leave it on the charger all the time? Is there some sort of trickle charger (similar to what I use on my Corvette to charge the lead battery during the winter) that you can buy for a lithium ion battery that gives it the necesssary voltage so it won't go dead? Other than that, I over inflated the tires and left the bike in the garage until spring. Thanks!