I set four main goals for the system in my work van:
- Automatic inverter on if car is on. I want the power tools, and the nowadays most important tool for a tech, the laptop, to be charged when arriving at the client site (Most of the time the shore power wont be available, since parking on random spots doesnt make this easy. I can connect it at some client sites or when on vacation, just have to snipe the correct curb side parking spot)
- DC system consisting of LED work lights, USB chargers and a small fridge
- Cerbo/VRM connection, as i want to play around with the capabilities of both, and have a system that i can test things on, like beta versions
- It needs to fit into the space under the seats, roughly 19cm high, 33cm deep and 120cm wide
So i came up with the following plan:
A few points i want to adress:
- Since i want the inverter to only be on if the car is running, for me the simplest way of doing this was trough a relay replacing the physical switch on the MP. Im sure its also possible trough NodeRed on the Cerbo, but my knowledge of how NR works is very limited. Its also a used unit, and im happy to modify things to my liking
(Digital inputs for On/Off/Charging are not working if the unit is also connected to a panel/cerbo on VE.Bus) - Other components are reused parts as well, like the DBL125s, the fan, some cabling, fasteners, the board the things are mounted on. Give components another life
- Switching to Charge instead of On if shore power is available is kind of redundant, since once its not available, the inverter is turned off either way, it wont go into inverting. I only noticed my mistake while testing, but since its no harm, i left it
- Im not sure if the additional diode in the trickle charger path is really necessary since the trickle charger is only connected if shore power is available. Still need to measure voltage drop across it. Datasheet says 1.2V but i measured 0.55V while it was on the bench. I may also ditch the relay contact if i decide to add the MPPT.
The rest should be just standard Victron stuff, with standard settings mostly, just some minor tweaks like adjusting the SmartShunt voltage to detect battery full at 14.2V instead of 13.5V and setting the MP to Lifepo/VE.Bus BMS.
The system is built and working, just need to tidy it up a bit to take some nice pictures 
