We want to be able to live as self-sufficiently as possible. For this reason we have installed two 100 Watt solar panels on the roof. The energy obtained is fed into a 110Ah gel battery via an MPPT solar charge controller. Should we nevertheless stay overnight on a camping site, we can also charge the battery via the mains voltage (110 - 230V) with the help of a battery charger. We have also installed an inverter that allows us to generate 230V mains voltage in the car. This means that we can operate commercially available electrical devices (e.g. electric shavers). We need the electricity generated by solar energy for the refrigerator, the auxiliary heating, the water pump, the radio, the light or the car sockets through which we charge our mobile phones, cameras, etc..
All consumers are centrally connected to a fuse box.
The water pump is only switched on by means of relays and the two switches (single-lever mixer, external socket) when it is really needed. This prevents us from flooding the car if a hose is no longer stuck, because the water pump only stops pumping when a water pressure of 2.8 bar is reached.
When it was a bit colder for the first time and we put our parking heater into operation together with all other power consumers, there was a power failure after a short time. After a short analysis we noticed that the parking heater needs more than 10A in the initial phase. Together with the electricity for the refrigerator, the light and the chargers, this is too much for the current output of the solar charge controller (max. 15A), which therefore switches itself off for self-protection.
Our solution: We have now connected the parking heater directly to the battery via a fuse, so that the output of the solar charge controller is no longer burdened by the parking heater.
Conclusion: The built-in solar charge controller is somewhat undersized for our purposes. In retrospect, we would probably buy another product from Victron. For example the SmartSolar MPPT 100/20 which has a 20A output and a built-in Bluetooth module (monitoring via smartphone).
Schematic diagram of our power supply: