You can get battery monitoring chargers these days that shut themselves off when the battery is charged to prevent boiling one dry. How that would work over 2-3 years I don't know since I've never stored a battery that long. While I'm not a battery expert Jerry's advise on putting it through occasional discharge/charge cycles sounds like good advise to me.

Save a life, adopt a senior shelter pet.
The three main causes of blindness: Cataracts, Politics, Religion.
Name your dog Naked so you can walk Naked in the park.