How best to look after leisure battery?

DiverPhil

 I have a M/H which is 22 mths old and the leisure battery is not holding a charge away from hook up. I use the van throughout the year but it does sit unused for up to 4 weeks at a time. I've never used it off hook up but have been thinking about it when
we next go to France. So I'm buying a new NUMAX 105AH this is a deep cycle battery. So my question is, what is the besy way to keep your leisure battery in good order? I do have a Ring Smart charger should I remove the battery and keep it on charger
when the van is not in use? grateful for any advice.

Phil