Thanks Jasper, I'll pull the wheels and repack the bearings if needed. I always forget these type of details until it's too late and I'm stuck in the middle of nowhere calling AAA.
RSCOTTP, here are the specs of the switch I used:
Battery Kill Safety Shut Off Disconnect Switch by Performance Plus Connection
.Easy to locate in emergency with "Bright Red Handle"
.250 amp continuous rating, 6-36 volt, 1000 peak [450 Rating Momentary]
.Helps prevent battery drain
.Required in NASCAR, SCCA, NHRA, IHRA, ADRL
I saw it at my dad's shop, he works on cars and such and I was visiting one weekend and he had it laying around. I priced it on Amazon and it runs about $30. If I didn't get this switch for free, I was considering just getting a cheapy circuit breaker. I just wanted to be able to shut the boat's electrical down in an instant if ever needed.
The charging unit I got at Walmart, it's an Attwood brand item. The first one I picked up didn't work out of the box, I had to return it and exchange for a new one. The second one seems to be working. I tried it out on my pontoon boat batteries and it charged those batteries just fine. On my pontoon, I just use 1 marine sealed battery for my fishfinder and a large 70lb thrust trolling motor. I can get a full day at the lake and still have charge left over. However, this little charger will take a week or two to bring the battery back up. I have a full size shop charger that I'll put on the battery for about 6 hours and then plug this little charger in and it will take another 2-4 hours or so with it and the battery is back at 100%. If you only go to the lake/river once a week, this little charger should do fine. The Attwood Battery Maintenance Charger by Attwood Marine Products runs about $30 as well.