Rookie boat owner here,thanks for any help or advice in advance! I left my shore power plugged in when I put my searay up for winter in my barn with the thought that it would keep batteries charged. Today I found a very heavy acid smell in the barn and the single battery on the port side was very hot,the 2 batteries on the sb side seemed fine. I am trying to figure the battery charging system and layout of the 3 batteries . I have been trying to find a schematic of the battery wiring to figure out which batteries are for starting and which one is for cabin accy. Is it a mistake to leave boat plugged in for winter? Battery maintainer a better idea? When plugged in are all 3 batteries supposed to charge? Thanks!