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joao-lima asked

Wiring diagram for a campervan (mercedes sprinter motorhome)

diagram.jpgHello everybody.

I'm doing the electrical project for a campervan. It is a mercedes sprinter 211 cdi van.

I made a diagram with Victron's equipment, for a moderate consumption, 2 days off-grid,


quant Watts volt Amps Amps in CC (12V) hour Wh Ah
Laptop Charger 1 65 230 0,3 5,2 2,0 130 10,4
mixer 1 700 230 3,0 55,8 0,2 140 11,2









USB 1 50 12 4,2
1,0 50 4,2
fridge 1 45 12 3,8
10,0 450 37,5
light 2 5 12 0,4
3,0 15 1,3
pump 1 42 12 3,5
0,5 21 1,8
exaust 1 40 12 3,3
1,0 40 3,3





total
846 70







Wh Ah

I wish someone could analyze the diagram and say if everything is correct.

Other questions

1)I have is about the multiplus temperature sensor. Are the black and red wire connected to the negative battery terminal? Where can I monitor this measurement, is it on the BMV 712?

2) I have a question about possible conflicts in the use of the multiplus 1200w and the 2 superpack batteries of 100A each.
My friend commented that: I may not be able to use them (batteries) with the 1200w Inverter, as it is very discharged for these particular batteries. Batteries have a continuous discharge capacity of 50A, while the inverter can consume up to 100A if it is fully charged. I will not damage the battery, as it can withstand a peak discharge of 100 A, but it is for a short period of time, so I will be able to find out that the internal controls will be activated and therefore will shut down the inverter. He recommends using the Smart Lithium line as an alternative and the external BMS. Is that correct? Would it be better to switch the batteries to the smart line? I chose superpack batteries because they are cheaper and have BMS included. What would be better, changing the batteries or changing the multiplus, if possible?

I await comments

Thanks

João Lima

wiring diagram
diagram.jpg (1.6 MiB)
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1 Answer
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Kevin Windrem answered ·

Nicely done.

The Multi's temp sensor leads are isolated from it's mounting tab, but Victron recommends connecting it to the battery negative terminal. For Lithium batteries it is not needed since temperature compensation isn't used. Make sure all your charging sources are set to a Lithium charging profile.

You won't see the temperature sensor's temperature anywhere in your system. If you desire battery temperature readout, there is a temperature sensor option for the BMV-712, but it looks like you've chosen the aux input for starter battery voltage monitoring. Another alternative would be a Venus system monitor (see below) to show battery temperature if it's really important.

You have two SuperPack batteries in parallel so your maximum continuous current is 100 amps which is about the maximum continuous draw from the Multi. The SuperPack batteries are probably OK as long as your DC loads don't add significantly to the Multi's draw on the battery. The extra margin of the Smart Lithiums with a VE.Bus BMS would give you extra margin.

Note that fuses and circuit breakers mainly protect the WIRING. Consider what happens if a wire is shorted. The one that stands out is the line between the starter battery and the Orion Charger. The one in the line to the Multi could also be in the wrong position.

You might consider a Venus system monitor like Cerbo/Touch 50 or CCGX. The BMV-712 could be replaced by a SmartShunt (less expensive) and the MPPT Control could be eliminated. Venus would then display all parameters in a better layout and in a central place.

A lower cost alternative to CCGX or Cerbo would be to use a Raspberry PI running Venus OS, then a touch screen connected to that. You'd need USB adapters for your MPPT and Multi. It's more of a DYI project but can save money. I switched from a CCGX to a RPI and love it, but I like to tinker. (Avoid PI 4s for the moment if you go that route. There are issues with some models not booting Venus OS.)

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