Battery info

There is probably an answer to this somewhere but have not see it yet. I opened up the trailer this weekend to get ready for three different weekends of camping this month. I had been charging the battery during the summer off and on. When I checked it, the water was down so brought it up to level. Plugged the main trailer line in and check the battery in about an hour. All the terminals we really hot and it was boiling badly. Is this a sign of a dead short in battery or do I have bigger problems?