Batteries- over the winter

[pair of jacks]

What's the concensus about removing your batteries over the winter. I usually do but a friend of mine says he disconnects his, leaves them on the boat and in the spring they are fine. Meanwhile, I've been hauling mine off the boat and trickle charging them once a month over the winter before putting them back on in the spring. Thing is that it's a major pain removing them due to the extremely cramped console access on the 21- you basically have to lie on your stomach and try to lift a 45 lb. battery out over wiring and such. Not easy. I used to be able to remove the tackle storage locker in the front of the console and lift straight up, put some of the screws stripped out over the years and the locker is now epoxyed in and can not be removed for access.
So do you guys remove batteries or not??