[Al Skierkiewicz]

T,
A normal by-product of the charge and discharge cycle is water vapor due to heat genrated within the cell. The vents open to release this pressure in the form of vapor. Even though the manufacturer says the battery can be charged in any orientation, I recommend that the battery only be charged in the upright position. Any liquid at the vent will be forced out when the cell pressure exceeds the vent trip. That liquid then pushes out of the vent. Following the charge cycle this water then recombines in the cell. As a battery loses water, it's peak capability is also lost. In gel cells this is more of an issue as the gel then decreases to the point were the plates are not fully covered by electrolyte. With gel cells it is/was easy to pickup a battery and actually feel the weight loss compared to a newer battery.