I have a 40A. Cir. Brkr. installed on top of my battery in series w/the Positive battery post to protect my trolling motor and wiring. Sometimes this thing will corrode quite badly after charging my battery. I am wondering if this is vapor from my battery caps causing this, and how can I correct it? Any ideas. It is a pain to clean. I have bought a spare breaker that I keep in my tool box if it fails.