Hey guys,I have two new trolling motor batteries (Rolls HT90 27 deep cycle) and the original trolling motor on my 1996 PII. A motorguide Brute 24v 55 lbs. After the last three times I took the boat out one battery was down to about 4.8 volts the other 12.1volts. I double checked to make sure they were fully charged before launch. Whats up with that? I checked the back of the TM plug and had 25.5 volts going into the motor after the batteries were recharged,. any thoughts?