I found this website that makes a battery maintainer that is suppose to eliminate sulfation and make your batteries last longer and even help restore older batteries. They have one that hooks dirrectly to the pack (PowerPulse 36 or 48 volt) and another that plugs into 110 volts (RediPulse 36 and 48 volt).
Has anyone had any experience with these? Do they work?
http://www.pulsetech.net/
http://pulsetech.net/productinfo/productinfo.html
Click the product application chart on the 2nd link and then you can see all the applications. If you click the red highlighted product name it will show you a picture.