Confused About Electrical Basics

After damaging and then replacing our original 560 battery with a poor substitute, we have damaged that battery as well and I've thrown up my hands and elected to upgrade the whole system to a lithium battery.

In consultation with Cary, I successfully took delivery of the same lithium battery CI is now installing with new camper builds. However, since I'm upgrading my system, I have a handful of other steps I have to navigate in order to do this. First, I'll have to swap out my CTEK (I have an older version that won't play nice with lithium) in order to have DC-DC charing from the tow vehicle. Second, I'll have to eventually install a new AC charger/tender. Finally, and this is the root of my question today, I will have to install a battery monitor since my trailer does not have the TriMetric.

I'm an admitted novice at any conversation of anything electrical, so please bear with me. I've consulted with some sales reps/dealers, and I have come to think that the Victron SmartShunt 500a battery monitor is a good solution for what I'm doing. The reasoning: most battery monitors include some sort of LCD screen that has to be mounted inside the trailer. As we all know, real estate is a little tight in the battery compartment and trailer. This SmartShunt actually doesn't have a screen at all - it has integrated bluetooth and relies on the user to "provide the screen" by way of a smart phone connection*. Therefore, the shunt can be installed inside the battery cavity and out of sight, and doesn't need any further bulkhead real estate for mounting a display.

I've reviewed the SmartShunt manual and also perused some YouTube educational videos trying to get a feel for how to handle the install. It honestly seems pretty simple and straight forward, but there is one big hangup that I'm sensing.

The install instructions first calls for the battery's negative terminal to be disconnected. The negative cable that had been on the battery now connects to the SmartShunt "System Load Minus" post. This represents all loads (accessories) and chargers. Then, a new battery cable is routed from the SmartShunt "Battery Minus" post to the negative post of the battery. By placing these two cables in this way, essentially all power that goes in or out of the battery flows "through" the shunt and allows it to measure/monitor things. A final simple connection from the SmartShunt to the positive terminal of the battery provides the monitor with the power it needs to work.

Here's what is confusing the snot out of me. When I consult the CI manual, the schematic for the battery/power wiring seems to suggest that the negative cable attached to my camper right now doesn't do anything but connect directly to the chassis ground stud. I don't see where any "loads and chargers" are integrated into that negative battery cable in the camper.

Am I reading this schematic wrong? My novice take-away is that the camper might actually be wired in a way that is incompatible with the product I'm looking at. Near far as I can tell, all of the "loads and chargers" are only connecting to the battery positive post. Is there a basic electrical concept I'm missing here?



*Of course, there is risk here just as with any product that relies on an app or software solution to run - the moment Victron decides to axe their app or stop supporting this model of battery monitor, the app won't work anymore and I could potentially have functioning battery monitor with no way to actually read the data. It would be a battery monitor that I cannot monitor, if that makes sense. I'm keen to that risk because I've recently witnessed the bad version of it from some friends who used the Kamado Joe temperature controller called iKamand. The device can only be controlled by a smartphone, which was great until Kamado Joe decided to stop producing and stop supporting the device. Overnight, folks who had spent 300 bucks on a temperature controller for their grill had nothing but a fancy brick that wouldn't even turn on.

 

The Victron Smart Shunt looks like a great product! I use the Victron Connect app with a couple of their chargers, and like it a lot.

I think your concerns about the connection to the Negative Post would be reduced if you opened up the battery compartment, removed the battery, and had a good look around. There you’ll find the Neg Post and see that all loads and chargers connect to it.

That’s one thing about reading schematics; one needs to compare the physical layout with the diagram and do some unhurried head scratching and tracing of wires to get the full picture!

 

Ahhhhh, so it is an electrical basic that I just wasn’t aware of. This is reassuring.

Before I had this camper (and before I got my Jeep Wrangle and installed a couple electrical items into it), my level of familiarity with electrical systems ended at screwing in light bulbs!

 

Electricity is not terribly complicated. Like anything start simple, and research. Videos on youtube are probably the best place to start. BUT....try to find ones that have high production quality. There's obviously the usual riff raff out there that is clueless and giving sketchy advise....

A good starting point is "https://www.youtube.com/@EngineeringMindset" --- his videos are all over the board but very well done.

This playlist is just on electricity and electronics basics...let me know what you think.

 

Bird, I replaced an old dead shore power battery charger with a NOCO5 installed inside the right hand galley compartment (instead of underneath- I'm not wild about sliding under to double check flashing lights)

and it was a giant PITA to either remove the rear bumper plus hitch or drop the water tanks...so I just left the old dead charger in place after disconnecting it. And put the new charger next to the battery.

I broke down and called Cary and Craig to confirm: "cut and cap this wire, and connect this other one, right?"...

My guess is you could mount the Noco10 there if not enough room inside the battery compartment.

Mine is an older model and a little trickier to rewire stuff, after a solar roof/CTEK upgrade, plus AutoX,
Which were also set inside the right storage compartment...

so it was easier to just stick the Noco5 in there too.

The addition of hard case Trimetric and wiring thru cabinetry is a bit intimidating to me, too...
And
my wiring skills and diagram/diagnostics are equally primitive...

So I'll be doing as you are- ordering the lithium battery locally and dropping it in myself.

And adding a bluetooth readout on phone app for monitoring LI capacity, vs hard sided TriMetric.

Victron seems to be one of the leaders in the biz...so hopefully enough aftermarket support to the app, for awhile.

So thanks for sharing, bookmarked thread to follow.

 

Yeah, it must be said that a factory-like install of a Trimetric or similar power/ah monitor requires passing a wire or wires through the countertop, preferably inside the corner of the right-hand upper cabinet in the galley.

For anyone who has taken the cabinet off, looked at that stainless-sheathed countertop, looked at the big glob of silicone caulk on the factory-installed bundle of cables the idea that you could self-install a power monitor by mounting a wireless solution completely within the battery compartment is a huge deal.

For us far, far away from Necedah who are DIY-ers the SmartShunt looks like a great solution to a common problem.

 

All good points you make. I have in fact not taken the counter apart or inspected the wiring or looked at the silicone, I just stared at the whole area for a minute and thought to myself “where the heck would I even mount something, there’s precious little real estate!”


Appreciate the crowd sourced concurrence - I went ahead and ordered the SmartShunt today. Another project for another weekend.

 

LOL!!! A perfect summary Lets see a photo of what you've done when complete

I'm wishing I added one of these when I bought mine now.

 

This is the charger that I installed replacing the OEM charger under the trailer between the tanks. It has Bluetooth monitoring capability and should eliminate the need for a separate monitoring device.

https://a.co/d/9SFADHc

 

Are you planning on solar or just AC charging? I don't see an external shunt on this --- so any charge coming from the solar controller would not be visible...

 

That’s the same charger I installed in our 560 with a new AGM battery, it’s working well!

I’m a little confused by this concern; a shunt like the OP’s SmartShunt is supposed to have *all* load and *all* chargers on the “to system” side, not the “to battery” side. At 500amps it should have capacity to handle alternator, solar, and AC charging simultaneously.

 

Not concern, just a question. Will the reporting on the charger include any other imports --- charging sources. I'm not 100% sure its really necessary except for the fact you woulnd't have a clear idea when the battery is about to die....since the voltage on LI batteries is so flat....

 

If properly installed it should monitor all charging sources and all discharging loads; that’s really the goal of monitoring for state of charge (SOC).

You’re right that any direct connections to the battery of loads or charging that bypass the monitor (SmartShunt) would make accurate monitoring impossible.

I think the product’s name is misleading. The Victron SmartShunt is primarily a monitor for a battery’s state of charge that includes a shunt across which current is measured over time.

So, you really should wire only the SmartShunt or other SOC monitor directly to the negative terminal! Nothing else should be connected to the negative terminal of the battery.

 

Looks like I missed seomthign then. There is a shunt on the battery (is it just me -- or does that word always sound wrong) the charger would get its input from the shunt that populates the app.

Then it makes complete sense.

 

No Solar now, but want to be Solar capable in the future. We got the 560 word with the solar input and the CTEK for that reason.

My understanding is the CTEK is wired into the system already so that when I connect the single (-)loads/chargers cable to the shunt (agree, weird word), the shunt will see any current coming into the battery from the CTEK.

 

That’s slick and would have saved me some money. My goal was to stay as close to CI “factory” as possible, so I will eventually be installing the same charger they are installing in new campers with the lithium option. The only non-CI component I will have is the smart shunt monitor.

 

I'm the first to say it --- sometimes I'm as dense as ironwood. This was the case. I see you installed the smartshunt --- and again I say, doesn't that word just sound wrong?

As long as you are connecting do the shunt on the end farthest away from the battery post....you're good. For some stupid reason I thought the shunt was internal to the charger which would be a problem since then it couldn't "see" the electrons from solar.

I added noise instead of clarity, and I hate when I do that...it sounds like you've got this!!!!

 

Sweeney, it is a weird word.
You shunt ever say shunt.

 

Wouldn't be so bad --- but my IRL name is remarkably similar ... That may be why it weirds me out so much...

But that's saying too much for COMSEC

 

Whelp, I installed a (Victron knock-off) Fusion Energy TBD-SmartShunt bluetooth battery monitor (link) in our 560 yesterday. About half the price of the Victron. I’m thrifty…

It is doing fine, giving good state of charge % info as well as current amp-hours in and out, and estimated time to a user-entered SoC minimum based on current load.

It would have been a straightforward install except my battery compartment is fulla’ other stuff I installed, and it starts off pretty tight from CI. There is NO MORE room in there, and I have to stop doing these electrical add-ons!