When I cover the MH and put her for the winter months I thought all well. So when I went out today and open her up just see if everything was OK. I HAD THE AWFUL SMELL IN THE MH. I thought I had left something in the black holding tank and since it was covered all that smell went into the MH.I have been airing out all day today. Then I found out that the engine battery was cooking. the plates inside was destroyed (NO WATER IN 3 CELLS) I just went and got a new battery and put it in.Looklike it something all the time. THE MORAL OF MY STORY IS always check all your batteries and see it you need to add some distill water.