Hi thanks for the reply, the battery is a sealed one .Welcome to the forum, there are many things that can draw on your battery.
Have you turned off the main power in the caravan, ?
The TV aerial booster ( if you have one ) can draw power.
The radio fromt panel can draw the power.
The caravan alarm draws power. On some fridges the control panel draws power
Is it a battery that need to be topped up with distilled water, do any of the cells need water ?