I have an Energizer Wet 12V lead Acid car battery that I had pulled from my 93 Aerostar for the winter and has been sitting in the corner of my basement workshop on one of my work benches. It has been connected to a new CTEK 3300 US 3.3AMP plug it and forget it type desulphation maintenance chargers for the past week. I noticed last night that the CTEK was back in charging mode which usually happens when the Battery dips below 12.9volts...no big deal. Today I was in my workshop again and noticed it was still in charging mode and when I'm right next the Battery I can hear small gurgling noises and the battery casing is slightly warm to the touch. I stopped the charger and popped off one of the vent caps and there are small air bubbles coming to the surface from between the plates. There is no smell, or heat coming from the open vents caps but is this normal behavior I have never seen this before. I also checked the battery with a multimeter last night it was above 12volts and today I took a reading a few minutes after stopping the charger and its now at 11.34volts?