I would charge the battery to 100% and then remove it and take it to have it load tested. Cost is only for your time and you will have accurate information as to whether the battery needs to be replaced or not.
The fridge electronics can consume 5amps over a 24 hour period. Inverters can generate a load even when nothing is powered on downstream. Instant on stereos and TV's will draw power all the time.
When I added solar the new digital meter would show a 80% charge level while the factory LED gauge still showed 100% charge level. A Trimetric meter is a good way to monitor what is going into the batteries and exactly what is being drawn out.