Red Zebra beat me to it. You can see my review of the BattryMINDER 1500 here http://www.tractorbynet.com/forums/...teryminder-1500-review.html?highlight=battery if interested. I love that thing, and it's seems to have extended the life of my batteries. The cheaper tender styles work too, but they aren't as smart and don't have the same desulfator system. But they do keep the batteries topped off and ready to start.