hot battery?

[mcleoud151]

My battery (an optima red top) is getting really hot after a 20 minute or more drive, and leaking the fluid out of the top (the place where the foam is). I know this is really bad, but can't figure out why it's happening. I put hte optima in because the last battery (Carquest brand) was leaking fluid out of it's caps as well. Anyone had this happen? new voltage regulator, and the charging system and everything seems to be workign well. Maybe overcharging it?

PS: How tough is it to replace all the underhood wiring (w/ the wiring harnesses, for example, from chevy duty or Year One)? The electrical in this is giving me a migraine!!!!