Should I Leave My Van Hooked Up Whilst At Home?

Is there any benefit from keeping you van hooked up to the electric when not using it at home?

Many years ago when I had a yacht, I was told that permanent hook-up kept the leisure battery topped up and therefore extended it's life span and prevented "deep-cycling". I didn't have a hook-up on the boat so it wasn't a big issue then.

However, at home, I keep the van hooked up but, as the leisure battery is not being used, I'm wondering if there is any need for this. The control panel always shows some input ampage so the power must be going somewhere!

Sorry if this is a stupid question but I'm new to this game and still finding my feet.

Martin.