I have a small bass raider 8e and when coming in from the lake today I was unscrewing wing nuts on my sears die hard deep cycle battery and I noticed (with some pain) that the wing nut on the + was extremely hot. I have never had this happen before but it is a little older battery. What would be the cause of this and is it safe to use? I put it on a trickle cherger overnight after every outing and have had no problems. Just wondering....