Battery Connections and Monitoring Help

[Euclid]

Hello all,

We’re looking for some advice in case anyone has been there, done that.

We recently bought a 2021 Flying Cloud 27FB Twin. The previous (original) owner had 4 100w Zamp panels installed, two Battle Born 100Ah lithium batteries, and a Victron MPPT 100/50 charge controller. Already installed from the factory is a Progressive Dynamics 1000w inverter.

We’re looking to install a Victron Smart Shunt, but after taking a look at the current electrical setup, we’re leaning towards also installing a Victron Lynx Distributor. If you’re reading and planning to give your two cents, you likely know that we want to install the Smart Shunt so we can accurately monitor our batteries. The reason for installing the Lynx Distributor is that our under bed and battery compartments look like a bowl of colorful spaghetti. Aside from being a neat-freaks, the current setup (pictures included) is hard to diagnose and not the optimal setup.

Which leads to our question; has anyone with this model done what we would like to do? If so, any recommendations on where to install the Smart Shunt and Distributor? Anything we should be mindful of that could make the installs complicated or cause issues? We’re not electricians, but are ok with following step-by-step instructions and these two components look “doable.”

Thanks in advance

[daleyocum]

I’d suggest the cleanest is installing the Lynx in the rats nest compartment and bringing heavier, like 0/2, wire from the battery inside the trailer to that distributor. When you are done, all the negatives should be coming from one terminal of a battery and all the positives from the positive on the other battery. That ensures both batteries work equally hard avoiding the problem I had where I killed my lithium bank.

Currently, both pairs of the thicker 6ga wires may into that rats nest anyway. The inverters ones certainly do. One pair for the inverter and the others go to the DC distribution panel which may or may not route through that compartment. If those don’t go through the compartment currently, you’ll be routing them now to connect to the Lynx. The zip cord pair is for the Zamp charging port. The Zamp needs to go inside anyway since you want it downstream from the shunt if you are going to use external solar. Heck, while you are there may as well run it into the solar controller and remove any controller from the external panel.

You may want to install a master disconnect switch right before the shunt so you can truly store your trailer. The Use/store switch in Airstreams doesn’t turn off everything and you’ll find your battery is dead after a month or so. If you leave it parked in the sun I suppose you could count on the solar to keep the batteries topped off. Still, a master disconnect is best.

I assume you’d get the Lynx shunt and Lynx Distributor. You might want the Lynx power-in though I think for a small install like this you can do straight into the Lynx Shunt (verify this.)

[Euclid]

Thanks so much! Good info. I was wondering about the OEM store switch. Likewise, thanks for confirming my suspicions about multiple connections across both battery terminals. I currently have a Smart Shunt 500a, but was wondering if I shouldn’t just go with the Lynx Shunt if I’m going to be adding the Lynx Distributor.

Cheers

[jeffmc306]

Euclid, congratulations on your new to you Airstream and welcome to the forums!

I can offer my experience with a 27’ Globetrotter where I installed a Lynx Distributor as part of a Victron MultiPlus II upgrade. I did clean up the rats next by shortening the wires one at a time.

I already had a BMV-712 so that was reused. The SmartShunt wasn’t available when I bought it. You could go with either the Lynx Shunt or a SmartShunt. I found the Distributor worked great because it consolidated all the positive and negative connections plus fuses in one place.

I chose to install everything inside the front compartment but you could install yours in the curb side compartment if that’s more convenient for you. I have electrical experience but did a lot of research before starting. I invested in a TEMCO crimp tool so I could make my own 4/0 cables and smaller ones. While you can order premade cables from batterycablesusa.com, I did make several changes during the build.

I did install a BlueSea master disconnect along with a Class T 400A fuse.

Good luck with your project!

[Euclid]

Thanks for taking time to share your experience. I usually look for excuses to buy new tools, but originally figured I would just buy the pre made cables. After researching and seeing the rabbit hole quickly approaching, I’m leaning towards getting the tools and making my own cables. Rather have options and be able to get it right. So much for a quick little project….

Really appreciate your input!

[daleyocum]

Originally Posted by Euclid

Thanks so much! Good info. I was wondering about the OEM store switch. Likewise, thanks for confirming my suspicions about multiple connections across both battery terminals. I currently have a Smart Shunt 500a, but was wondering if I shouldn’t just go with the Lynx Shunt if I’m going to be adding the Lynx Distributor.

Cheers

If you already have a 500a SmartShunt it’s fine to use that as well. Not quite as clean and it needs another fat cable but it should work just fine.

This rabbit hole can go pretty deep. Don’t be surprised if you find yourself installing a bunch of new batteries inside someday and putting in a 3000w Victron Multiplus inverter charger. Having every outlet in the trailer live while boondocking and being able to run microwaves, hair driers, coffee makers, etc is pretty great. Your FB twin layout makes that easier than some other AS layouts. Here’s mine for a 25FBT.

This iteration uses two 270ah Gamechanger 3 batteries in the outer compartment which fees up the majority of the two compartments under the bed. Previously I had five 100ah batteries in those inside compartments.

[uncle_bob]

Hi

There are a *lot* of components out there that you can use to "clean up" a wiring mess. There's really nothing special about the Lynx other than the pretty blue color. It is an expensive way to go. The Lynx shunt is an even more expensive way to go. Neither one really adds anything significant to the setup.

Yes, I'm a Victron freak and recommend them a lot. This is one case that I'd look at some of the other folks (like Blue Sea ....).

Bob

[waninae39]

+1 on using victron to monitor your system

[jeffmc306]

Originally Posted by uncle_bob

Hi

There are a *lot* of components out there that you can use to "clean up" a wiring mess. There's really nothing special about the Lynx other than the pretty blue color. It is an expensive way to go. The Lynx shunt is an even more expensive way to go. Neither one really adds anything significant to the setup.

Yes, I'm a Victron freak and recommend them a lot. This is one case that I'd look at some of the other folks (like Blue Sea ....).

Bob

Hi,

Have you done the math on the cost to do what a Lynx Distributor does vs. individual components? Nate at Explorist Life did a video and he showed it’s not more expensive. In fact, if you use all four slots it’s less expensive.

While we all love “the Blue” Victron components, this one saves space along with being cost effective. YMMV

Jeff

[Euclid]

Originally Posted by daleyocum

If you already have a 500a SmartShunt it’s fine to use that as well. Not quite as clean and it needs another fat cable but it should work just fine.

This rabbit hole can go pretty deep. Don’t be surprised if you find yourself installing a bunch of new batteries inside someday and putting in a 3000w Victron Multiplus inverter charger. Having every outlet in the trailer live while boondocking and being able to run microwaves, hair driers, coffee makers, etc is pretty great. Your FB twin layout makes that easier than some other AS layouts. Here’s mine for a 25FBT.

This iteration uses two 270ah Gamechanger 3 batteries in the outer compartment which fees up the majority of the two compartments under the bed. Previously I had five 100ah batteries in those inside compartments.

Funny you say that. Probably TMI, but the reason I have this AS is because I was going to add an entire solar kit and 3000w Victron MIC etc to our 2016 ORV Creekside. But, that meant resealing the roof, taking out the outdoor kitchen, buying all the components, etc…. Decided to look at other options instead of dropping 10k+ on the ORV. We always loved AS, so we explored and were graced with a heckuva deal.

The current solar and battery setup is a definite upgrade for us mostly boondockers, but rest assured, I have plans!

[Euclid]

Originally Posted by jeffmc306

Hi,

Have you done the math on the cost to do what a Lynx Distributor does vs. individual components? Nate at Explorist Life did a video and he showed it’s not more expensive. In fact, if you use all four slots it’s less expensive.

While we all love “the Blue” Victron components, this one saves space along with being cost effective. YMMV

Jeff

Thanks Jeff. Yes, while researching to build a system from scratch (post above) I watched many-an-hour of Nate at Explorist Life. I am a natural skeptic and penny-pincher, so I reflexively dismiss the suggestion to just go with the “popular” or “consensus best” brands that YouTuber pro’s offer. But, I love research rabbit holes, and at this point, I agree that the Lynx Distributor isn’t more expensive when buying individual components of equal quality. Hence, my reason for going that route. There may likely be a better setup, but the ROI on finding that isn’t in my budget at this point.

That said, I’m going to stick with the Smart Shunt so I can have Bluetooth monitoring without having to add a Lynx Shunt and Cerbo (also, less scratch.)

We’ll see how it works out. Thanks for taking time to chime in. Appreciate it.

[Euclid]

New to this forum stuff, so just want to say thanks for taking time out of your schedules to opine and help out. Really appreciate it.

A couple follow up questions for you all after seeing your setups:

What is your preferred method for securing the components? I really don’t want to mount anything (components or mounting boards) into the shell of the trailer. If possible, I’d like to keep my stuff in the curbside front under-bed compartment, but space is tight with that rat’s nest.

Also, I’m planning on adding a battery on/off switch before the distributor; do you all recommend/suggest adding a fuse on the positive cable before the switch?

Thanks again

[jeffmc306]

Definitely install a fuse between the battery positive and the disconnect switch. I used a BlueSea Type T fuse holder.

I used a left over 1/2” maple plywood to mount the components then attach to the wall inside the front compartment. You could do the same on the curb side. It’s a lot easier to do your layout and pre-wiring between components (if necessary) on the bench before transferring to the trailer.

The photo below was a mockup when I started but I made changes along the way. It helped me to visualize things.

[Euclid]

Awesome, thanks Jeff!

[uncle_bob]

Hi

All you *need* to clean up the mess is a connection bar for the positive and one for the negative.

Blue Sea will happily sell you any of a number of different ones for < $30 each. They also will sell you combo's if you want to go that way. There are a lot of folks out there who sell similar high quality stuff at about the same prices.

The Bluetooth Smart Shunt from Victron sells for $100.

So, cost done "the simple way" is < $160 depending on your choices. That includes the shunt. Lynx plus the Lynx shunt is > 2X that and likely 3X if you add a few other Lynx bits.

Bob

[JeffKim]

If you are going to go to all that trouble, with our 25' FBT I found it very helpful to first do a schematic of how everything fits together, to get the fusing right and flush out any confusion. I used DrawIO freeware. You can also post it and get a critique from us self-appointed experts (FWIW).

I'm on the JeffMc side of the Lynx argument, it keeps everything together in one nice box. You don't need anything else if you go with the standard shunt. There's a hack in Explorist to power the fuse lights with a 5V converter that tucks inside and has been working for me.

If you are going to all that trouble, moving the batteries inside makes everything much easier over running 0/2 wire back into the trailer. The batteries are well protected, stay warmer in the cold, and you will have room for two more if the time comes. It takes weight off the hitch and you get the battery box to put stuff in.

For tools I found this lug crimper worked good enough. Good wire strippers, connector crimping tool, ferrule crimpler, and the mighty Klein cable cutter which with a delicate touch can be used for stripping and worth every penny.