with distilled water that is. I'm asking this because it seems like most batteries I have, even without top off, last nearly till the end of the warranty period (i.e. 60 months out of a 72 months warranty). How much longer will they last if I do top them off? I'm lazy and with so many things on my mind, I'd leave the battery alone if it doesn't make much of a difference. I'm also afraid of overfilling and have the battery acid spill out.