Battery capacity fall-off

MrBigFeet
MrBigFeet Forum Participant Posts: 5
edited October 2015 in Caravans #1

Has anyone experienced the capacity of their caravan or motorhome battery falls off very quickly? My new-in-January 2014 115Ah battery didn't seem to last very long off mains. I charged it up and put a 5 amp load on it (20 hour rate). I timed it down to
10.5 volts. In December 2014 I got 80Ah. I just repeated this and got 57Ah. The battery has a 3 year warranty but the supplier says the battery is not faulty and this is what they do. Sure defeats the object of paying more for a "better" battery.