Battery charging for a motor mover

We have recently changed our caravan and our new one has a motor mover - a wonderful addition for us!  However, the previous owner said that it was not adviseable to remove the caravan battery to keep on trickle charge (as we had with our previous one) as he said that it wound interfere with the memory of the mover.

Now, I have no idea if this is correct, but unless we charge the battery over the winter period, we are going to have no luck with the mover when we wish to head out again in the spring.  Out van is currently at a secure storage so no chance of a hook up there....

Our caravan is a Compass Rallye 530/4 and the mover is a Carver.

I would be most grateful for your advice and thoughts on this

(Bringing the van to our home to charge is not an option either unfortunately!)

Many thanks in advance