Hi everyone,
Here is my current setup.
Installed by myself with a control of the reseller to be certain I don’t f** it up 
Multiplus II 48/15.000/200
MPPT 250/100
Cerbo-S GX
2 Pylontech US5000 (going to be, at least, four of them when I’ll start living on the boat).
12 solars panels JA Solar 430Wc Fullblack.
cheers
Why did you decide in favour of such a large multi? 
I hope for you that it doesn’t vibrate and hum too much on the plywood. You would probably have to decouple it a little acoustically on a boat.
I was not correctly advised by the vendor… I could have chosen the 10.000v 100amp and it would have been enough. But I cannot go back now.
Behind the plywood, I welded L shape of 8mm thick steel. the screws to attach the Multiplus are directly in that steel bar. It wont move a hair 
boats like that one are pretty affordable though ?
is the system to complement the shore supply or island mode ?
What brand of solar panels ?
JA Solar 430 Wc full black
So I made a mistake in my first post 
Pylontechs are completely reliable for SOC, properly proven, a shunt is superfluous for this configuration.
Nothing wrong with that wiring for those two batteries, pack is a bit small for that inverter, or rather the inverter is oversized for the application.
In any case, this section is not for critiques, by all means ask questions but, as repeated before, let’s keep it positive.
Indeed,
The max amp of those cables is 100amp.
In the futur, I’ll add 2 more US5000. When I do that, I will use DVCC and connect both master and end line battery to the Lynx like it is done on the 3 pack batteries in this video :
Hi Nick,
Yes, I wasn’t correctly advised for the inverter, the 48/10.000 would have been enough.
As I do not live yet on the boat, I’ve ordered only 2 batteries. But when I move in, I’ll add, at least, 2 batteries to the actual stack.
Your setup looks great, just follow the pylon docs as I notice they are 5000’s not 3000’s without my reading goggles.
Iirc they allow a stack of 3 so you will need to extend your busbar/lynx to accommodate them, two stacks of 2 will be best and will distribute the load across the additional cabling. The GX will show you what the max DCL is regardless.
Cabling is based on what you intend to draw, on a larger inverter you can set limits as well, you also have the option to use both +'ve and -'ve ports on each stack, but 4 sets would be overkill if you intend to remain below 10kVA.
If I setup a second pack of two batteries. Do I need a separate Victron BMS cable ? I don’t know if I’ve enough communication ports on my Cerbo-S GX
No, just daisy chain them as per the pylon guide. Convention is the newest battery is always master though. They are only “separated” by their own DC cabling, still one logical pack of batteries.
So this is what it means…
I didn’t touched the setup made by my reseller. The only thing I did was the physical installation and preparing the cables without plugging them to each other. As I’m a complete noob in the solar/DC electricity, I let him finish the installation himself.
The only thing I did was to setup the AC OUT 2 to be turned on at 95% SoC and turn of when SoC goes below 50%
Thinking of it, I’ve told that to the reseller and he answered me he didn’t know it was possible
iirc the new firmware on 5000’s are 80A per battery under ideal conditions, the BMS will vary CCL and DCL based on battery charge levels. Ultimately you can limit the protection on the wiring to prevent issues, which will be driven by loads.
The short-term fix is to add a second pair of cables to the open connectors on the battery, if you need to draw more than what is currently installed.
Based on what I learned here,
I’m going to update the schema of the actual installation and draw another with the project.
Taking in account the battery DCL.
I remember having a discussion with my reseller about the mega fuses installed in the Lynx.
I think I’m gonna add a Lynx power in for the 2 pack of batteries and I’ll plug the loads on the Lynx distributor
Go for a Lynx Distributor with Adler EF3 fuses replacing the Mega fuses.
With the Lynx Distributor and an Open Source Script you can Monitor the fuses and get alarms.
Search for it in this community.
The Adler EF3 fuses (white ceramic block) can clear 50.000A instead of mega fuses with 2.000A. They cost around 15-30 EUR each.
I’ll have a look into it !
Thanks Björn
I’ve read this topic AIC Ratings for LiFePO4 - Class T - MRBF
It was a lot of thing that I don’t fully understand after the first read. But, If I’m not mistaken, the best way would be to use T-Class fuses for the batteries. As I’m going to use 2 pack of 2 US5000, a lynx Class-T would be enough and compatible to my actual Lynx distributor
I didn’t get the difference between Class-T and EF3 fuses. I’ll dig into it
Mega fuses can clear currents up to 2000A. Above that short circuit current there might be an electric arc. Important for 48V batteries with 280Ah +.
The Adler EF3 fit into Mega fuse holders, but can clear up to 50.000A.
The T-class fuse is similar to Adler EF3, but with other form factor. The T-class Lynx has only two ports compared to Mega Lynx with four ports.
With Adler EF3 you get same high current safety but for less money and more ports or less Distributors (again less money).
Mega-fuse Lynx Distributor equipped with Adler EF3 fuses for my batteries:
Other option for bigger battery banks are special NH00 fuses and holders for telecommunication which can break up to 800A at 48V and clear much higher short circuit currents.
Jean Mueller NH00 80V/800A fuse for special NH00 holders:
This holders can be used as switch.
I haven’t found a distributor for end customers yet.
