A few years ago, I had a 8 volt battery into the Troy car club in 1999. Yesterday, I noticed that the charger still in 5 amperes at pumping. Never happened before. I could hear the sound of boiling. Later that day, the use of the car, I disconnect all the batteries, and test voltage digital electric meter. In the 8.31 - 8.33 volt 5 test batteries. One test in 6.2. Obviously, that must be removed, but the new battery in the mixture will affect others life?