[tubman]

I have battery tenders on my cars when I go to Florida for 6 months every winter. I was concerned about overcharging, so I bought a simple timer from K-Mart. After a few months of experimentation, I found that if you set the timer to power up the maintainers for 15 minutes a day, it will keep the batteries up without worrying about overcharging and boiling. It cost me $6.99.