Battery life expectancy

mickrumble

Hello all,, I have a 4 berth middle size sort of caravan fitted with a motor mover. We bought it used from a large dealer 4years ago. We mainly use it on clbsites where the ehu is used quite heavily' The 110 amp hour leisure battery is now failing to maintain
charge as well as it used to. Thebattery was new when we bought the van.How long would you expect the battery to last in these conditions?