Any suggestions how I could do it?

If you buy a CTEK charger then one of the options is a pair of wander leads that you can permanently attach to the battery terminals. These have push fit connector on the other end so you can quickly connect/disconnect. Could you feed these wander leads to a more accessible location. https://www.plymouthbattery.co.uk/type/chargers/ctek-chargers

Colin

@JohnM20  .... I had considered seeing if I could connect to the battery side of the motor mover master switch which is inside the bed locker, adjacent to the back of the battery box 

That's exactly what I did with my last caravan using the  Ctek connector that eribaM suggested. Obviously remember to flip the caravan's charger breaker/switch before using the Ctek 👍

Can you not connect an EHU cable and leave the caravan to do it's own thing.

That is exactly what I have done for the last few years as mentioned in the OP. 

I'm assuming that the wander leads don't need to be particularly heavy duty. The ones on my old (and now defunct charger) are very thin.

Well not quite! you have had the charger just coming on for two hours a day.

What is the reasoning for not letting the on board charger get on with things, like it would on site?

To answer your question, yes, I think you are.

John

I also wonder if you are trying to over complicate matters. If, doing as you do now, keeps the caravan battery in good condition why bother changing things. It seems a similar set up to what I had for many years when I had a caravan. Indeed I still keep the motorhome connected to the mains for several hours a day despite also having a solar panel. The only difference with a motorhome is that you have to keep two batteries in good condition and to achieve that I have had a Battery Master fitted to ensure some charge gets to the engine battery.

David

I don't understand what the problem is.  I also have to use the MM to get our van on the drive - it's impossible otherwise.  The van is permanently connected by its EHU lead and the charger is on 24/7.  I've done this for the last 9 years with two vans and never had a problem.  Yes, I do think you're causing unnecessary work.

A few years ago, whilst talking to the tech guys at Sargent it was suggested that I didn't leave the charger on 24/7 especially if there was no draw on the battery. Switch it off after about 1 month was the suggestion / recommendation. Consequently I set up the two hours per day charge (just a timer on the EHU cable) which seems to have worked absolutely fine. This adequately maintains the voltage at 12.7.and, of course, isn't charging continually.

The reason for thinking about utilising a smart charger was in view of the various posts on here that advocate taking the battery off the caravan, especially over winter, and give it 'a proper charge' with a smart charger.

I think this one breaks down to how good the charger/booster unit is in your caravan.

The correct way to maintain a battery is to charge and discharge it. Secondly would be a smart charger and finally is possibly your caravans unit. I know in my case that the Schaudt csv unit fitted is suitable for being left on 24/7. I have done so with different versions of this unit in my 4 Eriba's over 20 years.I have not needed to replace a battery. 

Colin