Whoa, be careful out there! An overheated battery could very easily explode. If you're in the neighborhood of an exploding battery you'd have a real problem. Like mentioned previously it could be a shorted cell or the converter is overcharging the battery. Don't keep it plugged in long term until you find the problem.
2015 Greyhawk 29MV
Honda CRV toad with Blue Ox baseplate
Ready Brute Elite towbar with braking system
TST 507 Flowthru TPMS