Question to the battery experts

As a non-specialist a question to the battery experts. I want to connect a 12 V can for the outside directly to the board/mover battery so that I have available both at short notice self-sufficiently, as well as generally 12 V in outdoor. Now the question: The CP is connected to 230 V and thus also the charger for the Mover battery that means that it is constantly charged. Is this usually enough when electricity is pulled from the battery at the same time? If, then not much, possibly H andycharging, or (only in an emergency) a cooling unit/box for a short time. However, I also want to switch a night lighting on a case by case basis. This means the WW is connected to 220 V, but the 12 V should be directed from the 12V-box into the suspension box on the corresponding PIN`s to illuminate the WW on the front door at night. Thus the mover battery is loaded, but also charged at the same time by the charger. adung from the charger is sufficient to operate that, or should I rather attach an external 220V > to 12 V converter?