Caravan Alternator + Solar - wiring review & sanity check

[Cannabat]

I have made up a rudimentary diagram for my WIP off-grid caravan build. Would some experienced folks please review my setup, particularly cabling and fuse sizing? I think I've chosen the correct cable sizes and appropriately conservative fuse/breaker sizes for the max load of the system (2000W surge).

My only major point of confusion is about grounding when not connected to my vehicle... I suppose I should just run another cable to the caravan chassis, as I have illustrated in the diagram - is that correct?

Thanks in advance for any guidance and advice.

My gear choices):
- 4 x 272Ah Lishen cells (review thread) - ORDERED
- 200A Daly BMS - ORDERED
- Renogy DCC50S for alternator and solar charging - RECEIVED
- Renogy 1000W inverter (2000W surge) - ORDERED
- Renogy 500A smart shunt with monitor - RECEIVED
- Blue Sea Systems circuit breakers and isolator switch (I want these to be high quality) - PENDING
- WindyNation 200A fuse - PENDING
- This power supply to top-balance my cells, and for use during the odd times we have shore power to charge up the battery bank - PENDING

The setup is almost exactly the usual build from Will's site, which I found only recently. My existing plans were already really close to Will's build so I just went all in.




Thank you!

 

[Cannabat]

Have made two changes:
- I had a big 300A switch on the battery negative. I realised it's better to have this on the positive. I have replaced the 200A fuse with a 200A Blue Sea Systems breaker, which will be panel-mounted and act as master kill switch, cutting off loads. It won't disconnect the DCC50S charger from the battery, though. Is this bad practice? Would I be better off with an additional dedicated switch, between the battery and the 200A fuse?
- I realised the smart shunt needs a small B+ connection, added this to my diagram.

 

[Cannabat]

I remade my diagram with images as the boring shapes were kinda hard to read for me.

I realised my main breaker was far over-rated. I've changed it from 200A to 150A. Calculation:

((1000W / 0.85 / 12v) + 20A) * 1.25 = 147.55A
    ^       ^            ^      ^
    |       |            |      |
    |       |            |  nuisance trip factor
    |       |            |
inverter    |        max DC load
            |
        inverter inefficiency

This means I can use the more affordable Blue Sea Systems 285 series breakers and still have a happy warm safe feeling when I sleep.

I have purchased a Riden RD6018w benchtop power supply (bundle including the case and 800W PSU) which will allow me to top balance my cells and charge them from 240v as needed, as well as be a nice supply to play around with.

My questions at this point:

1. When I disconnect the caravan from my tow vehicle, I lose the grounding to the starter battery/alternator. So am I correct in having an additional wire going to my chassis ground? I suppose I will just connect to a negative bus bar or whatever that the caravan electrical system provides?
2. I'd like to have a master kill switch for my system - but can't I just manually trip both the 70A and 150A breakers to totally kill all 12v and 240v loads, right? I mean, it's two switch instead of one, but it's simpler...
3. At this point, we haven't purchased the caravan yet. It may have come with some rooftop panels. If so, I don't think it will be enough, so I'd be adding a couple additional (identical) portable panels. They would be wired in parallel - they would require a separate MPPT charge controller if their open circuit voltage and max output current were different than the rooftop panels, yeah?