buy the fuse box and mega/midi fuses
Ebay and Amazon could be a source. These are standard automotive fuses so should be available from an auto electrical specialist. I suggest buying from a company in Europe rather than aliexpress ( assuming you are based in France)
"combined version", it means that I wouldn't need my positive bus bar anymore ?
Yes, the fuse distribution holder effectively combines the buss bar and fuse holders, the style in the picture having one mega fuse position and 4 midi fuse.
Is it correct to keep my 120A mega fuse ?
This is the 'master' fuse fitted as close as practical to the battery positive post.
Any cable regardless of length should be fused to protect the cable from currents higher than the rated maximum.
The absolute maximum allowed currents are, 10mm2, 70A, 16mm2 110A, 25mm2 170A.
The battery you are using is a lithium battery, should there be a fault somewhere in the circuit, ( a accidental connection between the positive and negative) and the BMS were to fail to protect, (open the output path) then the battery will deliver a very high current ( 1000s of amps) , this will melt cable insulation and cause a fire.
The automotive mega fuse is only rated for interrupting 2000 amps
in order of current interrupt performance using quality branded fuses with a 12v battery,
mega fuse, 2000 amps
ANL fuse , 6000 amps
MRBF fuse, 10,000 amps
Class T fuse, 20,000 amps
The Blue sea MRBF fuse and fuse holder, whilst not offering the highest protection of the Class T fuse, is acceptable in my view.
. I don't have the BMV but this one.
Component part and diagram changes make it difficult to offer advice. The Aili may give passable performance but does not have the programmable relay that the BMV series have.
Because you do not have the inverters connected to the Victron battery protect, any low voltage protection will have to be carried out by the battery BMS or the low voltage shutdown in the inverters.
This should be enough to protect the battery from low voltage.
If you need additional protection against low voltage for the fridge inverter, then the relay contacts in the Victron Battery Protect, could be added in series with the enable control to the inverter.
What BMS are you using? Is It user programmable?
Can the inverter low voltage shutdown levels be user programmed. if not what are they set at?
It would seem you have enough solar and battery capacity to power the fridge for long periods and its unlikely, since you have battery monitoring with the AiLi and perhaps a smart BMS, you will not allow the battery volts to fall too low.
In the unlikely event the battery becomes too discharged, the BMS will shutdown.
as the switch of my BMS is not shuting off the power in my circuit, should I add a breaker between MPPT and solar panels ?
What is usually done to turn off everything in the van ?
Fitting a switch between the panels and controller rated for the input DC current and voltage would disconnect the panels.
To completely isolate the system from the battery you could add a battery isolation switch between the 'master fuse' at the battery and the rest of the circuit.
Mike