I have the same Smart Solar MPPT 70/15. Assuming this is charging the leisure battery. I notice that the Load is in the off state, which I assume means the loads such as the heater are coming straight from the battery. I can’t remember if the load voltage is regulated as I link this to a 65A battery protect. A couple of questions:
- Are the 12 volt loads coming straight from the battery at the moment?
- Are you sure the heater and battery monitor are not connected to the starter battery. (The reported voltage difference would indicate they aren’t, as it appears the loads aren’t connected to the MPPT)
- Are you using a victron Smart Battery monitor? If so, have you created a VE Smart Network?
Please post a couple of photos showing the installation and how it is wired.