Tankless water heater

Got a Camplux Propane RV water heater last year and it's been solid.Been taking showers with it now for a few weeks at our off-grid cabin while we build our forever home nearby. I bought a small 12v battery that has it's own on/off switch, a 5-gallon bucket, and a small length of clear tubing for the over-pressure drain valve on the bottom of the water heater that feeds into the same bucket. So the only thing I will say is that temperature control is really based on the temperature of the water you freed it.