an inteligent charger is all you need, one with an automatic cutoff.
Mine is one that is suitable for a leisure battery, I have no choice as to whether or not it is on boost or trickle, I plug it in and a red light comes on to say it is charging.
In the morning there is a red light on to say it is charged!
Better still, if you are using a van mount setup, get yourself sorted with a split charge relay on the van itself, then you no longer have to worry about the battery being charged or going flat again
And you should be able to get one fitted for not much more than the cost of a decent stand alone battery charger too.
If you are using a trolley or a backpack then you will need a separate charger of course.
On the charger I have, it also said what amp hour batteries it was suitable for.
The bigger and more powerful the battery, then you will need likewise with a charger.
Ian