Battery flat and lights no longer working

by Katherine
(Shetland)

Hello I am hoping you can help me. I bought my first caravan 3 months ago and have it plugged in via the correct cable on site at my property.

Until the other day all lights were working and when I pressed the battery test switch it was always up to the maximum level. The only things I am using in it are two small oil radiators, a light or two now and then and boiling the kettle.

Why would the battery suddenly die? I have the switch in the van set to van not car. The radiators are still working so power is coming through the cable. I can therefore only assume the lights inside the van run separately from the battery. What else am I missing.

Thank you for your advice.