We have a consistent surge every night between midnight and 2.30am. Nothing is being used apart from standard fridge and some lamps. How can we detect what is causing this high usage, therefore depleting our battery during the night? Our geyser is not supposed to be using the battery charge.
If you do not want the battery to be use to power the geyser, you could add a timer to the geyser circuit to limit when the geyser uses power.
How much PV and battery do you have?
Looking at the chart, you do appear to have some large load peaks.