Following has never happened before. Took battery out of caravan to give it a boost, had to walk about 40 m to garage and happened to look back along pathway and found long trail of "water". The battery is about six months old and is the so called non whatsit. On investigation underneath two labels about the battery found the usual filling caps . Looked inside and I had nearly emptied down to top of plates. The trail on the sandstone slabs have all been marked with the acid. Later it rained hard but when the slabs dried out the trail is still evident .It had all come out via the breather vents. As for me the battery being so heavy I used my sack truck and the vibration caused the problem.