Battery Problem

SteveYoung1

Bought a new 110 Leisure Battery for my caravan about 3.5 years ago, which has a motor mover.  I am having problems now with it powering the motor mover.  It only allows me to move it a couple of feet at a time.  Am i correct in thinking its probably the
battery?  A few months ago there was also deposits on one of the terminals.  Help.......