It depends on the battery capacity and consumption in the motorhome. You must also take into account the maximum recommended discharge of the battery, depending on whether it is AGM, Gel or LiFePO4 lithium (ferric lithium).
For example: with a 100Ah AGM caravan battery and a consumption of 50Ah per day (refrigerator, water pump, small appliances and lights), so as not to exceed the recommended 50% discharge, it will last us one day.< /p