The electrolyte level in all battery cells must be between the lines marked «MIN» and «MAX», applied to the translucent battery case. Do not operate a battery with an electrolyte level below the line marked «MIN».
During operation of the battery, the electrolyte level gradually decreases, as the water that is part of it evaporates. To restore the electrolyte level, add only distilled water.
If it is determined that sloshing is the cause of the low level, then top up with electrolyte of the same density as that remaining in the battery cell.
If the level is above normal, then reduce it with a rubber bulb with an ebonite tip.