General info on battery chargers:

Once upon a time they were unregulated, and could produce up to 20v - resulting in very hot batteries, and a lot of electrolyte in essence boiled off! Bad.

The TP2 and most integrated caravan chargers produce up to 13.8 volts and the current is regulated - sometimes to about 5 Amps but some less. However this does not I gather produce enough chemical action to de-phosphate the battery plates and does little if a battery ahs been neglected.

Modern car battery chargers produce up to 14.4 volts and are regulated according to their capacity, some 7A, some 10, some up to 20. This will often in effect "clean" the plates. By means of cunning electrickery, as the back emf rises (ie as the battery charges a bit) as the battery gets above about 11V, the charger voltage comes down to 13.8v and when the battery is fullycharged the charger goes down to "trickle" at about 13.5V and virtually no amps.

Essex Girl you may want to inform your electrician in case he is mostly mains oriented. I suspect you want to give your battery a good charge on a modern charger (check the electrolyte level), not in the van, then leave some lights on to drain it to a ways below the red warning light in the van, hoick it out again and re-charge on the modern charger. A modern woman can do that, no?