Help retrofitting Victron system - purchased RV

[NVCYberPro]

Hi, I need help and advice retrofitting a system that came installed on a 5th wheel trailer we just picked up.

The system consists of

Victron Multiplus II (12 | 3000 | 120)
Two 4s 280ah batteries with Overkill 120A BMS's
(has reptile heat pads on Renogy battery box)?
2 Renogy Rover Elite 40 Charge controllers each connected to 490W panel and breaker
1 BougeRV charge controller connected to a 490W panel and breaker
1 NewPowa charge controller connected to 3 180W panels in series and breaker.

These are all wired in parallel to bus bars and then to the rv's built in bus bar via a battery switch, the switch allows it to be connected to LiPo4 batteries, 12V Sealed Lead Acid Batteries, both LiPo4 and Lead Acid Batteries (huh?), or disconnected (off) from both battery banks.

I want to add some sort of fuse or breaker between each battery and the bus as I don't see anything there. Recommendations are appreciated here.

This is all in the front storage compartment of the trailer and I do not want to use a smart phone, blue tooth or wifi to control or monitor this system. I picked up a color control GX and a BMV-721 shunt and battery monitor as well as a MPPT 100/50 charge controller to add into the system. I would like to add the color control and possibly the battery monitor (not sure if needed) in the hall of the trailer, 15'+ away probably 20-25' as the cable flies.

I do not know what I need to connect the multiplus II, the MPPT charge controller, the shunt to the color control and possibly the battery gauge, Also I am not sure how to best integrate fuses into the battery cables, currently has anderson type connectors and lugs to the buss bars.

Thank you

 

[chrisski]

What do you think of this Victron Class T holer?

Lynx Class-T Power In | Victron Energy

The Lynx Class-T Power In connects and fuses up to two strings of Lithium batteries. It features a positive and negative busbar, and connections for two Class-T fuses as well as a connection to ground the DC system. The Class T-fuses, available in 225A, 250A, 350A and 400A, must be purchased...

www.victronenergy.com

To me, fusing the batteries becomes more of an issue of where will you put it. I use individual class T fuse and holder for Each Battery and after joined up, but that takes up a bit of space (7" X 2" X 2.5" each fuse holder) and spacing in an RV is critical.

 

[NVCYberPro]

Yes space is an issue I didn't mention. I plan to add a 2nd Multiplus II in the future as I plan to add a 2nd AC unit and believe I need a second inverter to handle the load, also plan to add two more 280ah batteries if possible. If I use the Lynx Class T Power then I need the Lynx Distributor as well?

 

[Dinobot248]

I'll try to help. Here are my random comments.

1. Have you checked on the previous owner's setup. Is it built well enough where you can leverage it as your foundation to expand your system.


2. If you want or plan on expanding, you should really consider going to 48v. Figure out what your electrical needs are and how you plan to RV.


One 48v MPPT can, in theory, support all your solar panels. I say "in theory" since if you were starting from the ground up, having similar or the same solar panels is best practice. That 100/50 is not ideal for a 48v system, but a 150/45 can support about 2600w if I recall correctly (58v x 45a = 2610w)

Your 3000VA / 2400W MP II requires battery cables supporting 200A. Too lazy too look up the required wire awg but that has to be at least 1/0. With a 48v base system, you would use 6awg to cover 50A (2400/51.2)


General rule is 12v systems are good for 3000w or less systems. Battery cables get more expensive and you will need 4x as many MPPTs when compared to an equivalent 48v MPPT. 3000/12v = 250A. That is thick cable




3. Looks like you may want the standard Victron ecosystem reporting functionality.

3A. For a standard and clean looking setup, you would WANT the following

Cerbo GX (e.g. cerbo gx, cerbo S, color control GX, or several other equivalent units where some have screens and others dont)
Lynx Shunt (e.g. Lynx shunt works for sure, I think the other shunts that have a ve.direct cable should work too)
Lynx PowerIn. This is a fance bus bar with no fuse holders. There are hacks but I won't mention them now.
Lynx Distributor. This is a fancy bus bar with fuse placeholders.
Victron SCC

3B. For a super barebones and not so clean looking setup, you would NEED the following

Cerbo GX (e.g. cerbo gx, cerbo S, color control GX, or several other equivalent units where some have screens and others dont)
Lynx Shunt (e.g. Lynx shunt works for sure, I think the other shunts that have a ve.direct cable should work too)

To answer your question above, No a Lynx distributor or PowerIn is not required, but they help make your wiring much cleaner. If you're already spending the money, just spend the extra $150 or so to get them.



4. Non-Victron SCCs will not be directly visible from a Victron compatiable screen (.e.g actual screen, phone screen)

One work around is to enable "DC systems" in the Cerbo GX or equivalent device. This will allow the system to list any unknown incoming or outgoing power as coming from your DC system.

5. If you choose to not enter the Victron ecosystem, you can still use a Victron shunt or any shunt for that matter, to monitor your overall battery SOC.

Hope this helps.

 

[HarryN]

I just use bluesea / Bus 187 breakers for each item. Dual feeds to the inverter when on 12 volt.

Change out that renogy charge controller as soon as feasible, they use as much standby power as having the inverter on.

The reason that I like having the breakers is that it makes it much easier to do battery BMS re-sets and to isolate off portions of the system to work on it. With just fuses, your system is always live, which can be exciting sometimes when trying to swap out things.

 

[chrisski]

You could very well have this finished by now.

If I use the Lynx Class T Power then I need the Lynx Distributor as well?

You could do your own distributor; however, I have found by doing something like that the bus bars you purchase could be slightly higher or lower and busbar copper has no flex.

I mated a class T fuse in a holder to a busbar for distribution and had to put spacers underneath one to secure it.

I did not use the Victron Lynx family for my RV build. It saved me money, but cost me days of time fabricating copper busbars from copper flat rod in the DIY research design and build, and I wish my connectors were covered as good as the Lynx was.

Victron makes good products for a cleaner easier install, but the cost adds up.