Need circuit diagram for hooking up Victron battery monitor

Photomom

We are camping now and using more power than my calculations seem to indicate. I am thinking of getting a Victron BMV-712 battery monitor. Jkjenn has a nice write up and the Victron folks have a video, but those are words and I’m a visual person. Does anyone have, or can point me to, an actual circuit diagram / schematic? Must include: battery, battery switch, Victron solar controller, shunt, and the battery monitor. A picture is worth, well, you know...

elbereth

Look at @jkjenn’s post of a photo near the bottom on Page 1 of this thread, I think it has what you need:

https://tab-rv.vanillacommunity.com/discussion/2113/big-data-for-a-tiny-trailer-battery-monitor-installation-victron-bmv-700/p1

Photomom

How does the solar controller connect?

BrianZ

The solar controller normally has a pos & neg line going to the battery; except all battery negative connections go to the monitor's shunt instead of directly to the battery, then the shunt connects to the battery negative.

N7SHG_Ham

The shunt hooks to negative terminal and ALL other negative wires to other side of shunt. Every electron into and out of the battery MUST flow through the shunt to get accurate picture of battery status.

Sharon_is_SAM

Here is a simple diagram.  This is how ours is set up.

(Edited to attach PDF instead of Word Doc.)

BrianZ

https://www.victronenergy.com/upload/documents/Hub-1-System-Layout-V3-4-8-2014ADR-.pdf

pthomas745

@Photomom , here are some photos I took when I first installed my Victron six months ago.  I've gotten it looking a bit nicer.  (Not much).  I've discovered with the Bluetooth app on my phone, the need to run wires and drill holes for the display seems less of a necessity.  It has traveled in a "hobby box" on my last few trips with no issues. 

I had to purchase a new cable that runs from the negative terminal of the battery to the "Battery Only" terminal of the shunt. That was the hardest part of the install. 

On the closeup of the shunt:  the two white wires originally ran to the negative terminal of the battery.  I disconnected them from the battery, and attached them to the "Load" terminal on the shunt. Those wires move into the wiring harness: one goes to the Battery Shutoff, the other goes to the Zamp port. 

The only reason to deal with the positive side of the battery connections was to add the small red wire from the shunt's B1 port to the positive terminal.

Photomom

pthomas745 said:

@Photomom , here are some photos I took when I first installed my Victron six months ago.  I've gotten it looking a bit nicer.  (Not much).  I've discovered with the Bluetooth app on my phone, the need to run wires and drill holes for the display seems less of a necessity.  It has traveled in a "hobby box" on my last few trips with no issues. 

I had to purchase a new cable that runs from the negative terminal of the battery to the "Battery Only" terminal of the shunt. That was the hardest part of the install. 

On the closeup of the shunt:  the two white wires originally ran to the negative terminal of the battery.  I disconnected them from the battery, and attached them to the "Load" terminal on the shunt. Those wires move into the wiring harness: one goes to the Battery Shutoff, the other goes to the Zamp port. 

The only reason to deal with the positive side of the battery connections was to add the small red wire from the shunt's B1 port to the positive terminal.

Did you leave the monitor and shunt just laying in there like that? I ask because I am looking for a simple installation, looking forward to a time when we might graduate from the T@B to something else. 

pthomas745

No, that was about the first afternoon when I plugged it all in.  I found a much smaller data cable between the shunt and the monitor.  The shunt is about 4 inches long.  I had a small plastic "tool box" that fit the shunt and the monitor, and drilled grooves for the wiring runs to pass through.   A better box is in my future.  (PS: I do wrap more plastic around the whole thing to protect from moisture.)

It is a simple installation.  It would take me 10 minutes to remove the shunt. Just a simple matter of unscrewing the battery terminals and reconnecting the negative wires back to the battery, and removing the B1 cable.

dCliffhanger

I noticed on my new T@B 320 S with solar that the Victron 10\75 was wired to only take input from the solar panels then to the battery. The +- Load terminals were not utilized at all. All 12 volt power is wired directly to the power ac\dc power unit. Therefore, the Victron is not monitoring any power draw\usage from the battery. I can use the bluetooth app to monitor charging and battery voltage but that's it. I asked Nucamp if I could redirect the wiring to have all the battery draw come through the Victron then to the ac\dc unit. They advised against it but recommend that I look for advice on this forum.  I'm not sure but that might require upgrading the Victron model to handle more amperage. The biggest single load I have is the frig, which draw about 11 amps. Bottom line is I'd like to monitor both the input and output of my Firefly carbon foam battery not just the input. Suggestions? Would the Victron BM-712 or such accomplish this more simply?

Cbusguy

The 712 is the answer.. you can make guestimates from your cell voltages but the 712 gives you a direct amp hour reading so no guessing how much juice is on your battery.   S
i
your battery goes south it will tell you.   My 100 amp hour battery is only taking 20 amp hours and reports full.....yep bad battery......

It can also help you more easily understand your power consumption.

There are cheaper alternatives.....but not Bluetooth or victron and they work just fine

dCliffhanger

Cbusguy Thanks that does sound workable. But, my basic question is why not run all the battery load through, the already existing and paid for, solar controller? The unit already has the power use monitoring capability, I think. Why spend another $200?  I have to say that I'm excited to see how this carbon foam battery performs. I can, per claims and reputation, be drawn down to nearly zero regularly,  and still come back without the kind damage that a normal deep cycle would incur.

pthomas745

The solar controller is a separate component which feeds power from the solar panel to the battery.  It can tell you (apparently) the battery charging status, as you point out.  (Still very useful information, BTW).    The Victron 712 is on the other side of the battery, monitoring what is being drawn from the battery. Turn on a device that uses one amp per hour, and an hour later the 712 will tell you that one amp has been used.  It tells you voltage and power consumption in real time. 

pthomas745

I wanted to update this thread with my almost finished Victron installation.  It took me a while, but I finally got the shunt out of the baggie and into a nice project box.  I'd like to thank Jenn and Brian Z and all the others who led us into the Victron Promised Land, and showed me what type of project box to find.

I am no sort of solderer or crimper of cables, so to get the wires in and out of the box I discovered "cable glands" that allowed the cables to pass through, and a box with pre-drilled holes.  I sealed the small gaps in the glands with some silicone, and the box will sit upside down.   I doubt the areas where the small wires pass through the gland are waterproof, so I will have to watch them.  I found a much shorter data cable (the telephone cable) and needed a longer, much more flexible negative battery cable.  The battery cable actually holds the shunt very tightly inside the box.  The Victron display will be held down with a bit of gaffer's tape, but it does not move very much.  The box will be attached to the side of the battery box with some industrial velcro.

Photomom

pthomas745 said:

I wanted to update this thread with my almost finished Victron installation.  It took me a while, but I finally got the shunt out of the baggie and into a nice project box.  I'd like to thank Jenn and Brian Z and all the others who led us into the Victron Promised Land, and showed me what type of project box to find.

I am no sort of solderer or crimper of cables, so to get the wires in and out of the box I discovered "cable glands" that allowed the cables to pass through, and a box with pre-drilled holes.  I sealed the small gaps in the glands with some silicone, and the box will sit upside down.   I doubt the areas where the small wires pass through the gland are waterproof, so I will have to watch them.  I found a much shorter data cable (the telephone cable) and needed a longer, much more flexible negative battery cable.  The battery cable actually holds the shunt very tightly inside the box.  The Victron display will be held down with a bit of gaffer's tape, but it does not move very much.  The box will be attached to the side of the battery box with some industrial velcro.

Thanks. I think the tub is a convenient place for the battery monitor. Are you planning to leave the display inside the project box?

Cbusguy

With the Bluetooth I left mine near the battery.   I didn't see the need to mount it in the living compartment and I can connect to it from inside the trailer

Photomom

Cbusguy said:

With the Bluetooth I left mine near the battery.   I didn't see the need to mount it in the living compartment and I can connect to it from inside the trailer

Is is inside the project box or outside?

pthomas745

@Photomom , yes, I'm going to leave it there.    I do like the looks of the display on the walls inside the camper, but I don't have the skills/tools to run the cables.  The bluetooth works just fine.

webers3

@pthomas745 I like your solution, also don't have the skills running the wires and installing inside the cabin. Would you post the details of the box you used?

Photomom

pthomas745 said:

@Photomom , yes, I'm going to leave it there.    I do like the looks of the display on the walls inside the camper, but I don't have the skills/tools to run the cables.  The bluetooth works just fine.

Thank you. I have my Victron solar controller in a box inside the tub and Bluetooth works fine for that.

FYI, I tried using Velcro on the plastic box and it wouldn’t stick. I bolted a couple of hooks to the metal tub and used a strong bungie cord to hold the box in place.

pthomas745

@webers3 I used this box:

https://www.amazon.com/gp/product/B075DKJ3LX/ref=ppx_yo_dt_b_asin_title_o05_s01?ie=UTF8&psc=1

It fit the shunt and the display easily, but it was a bit close on the cover.  There were plenty of pre-drilled holes for me to experiment with.  Those little rubbery grommets pop out.  The big size cable gland nut sealed against the hole but the smaller one did not.  I sealed them both with sealant. I thought I might need to use small screws to mount the shunt, but the battery cable is thick enough to hold it tightly in place.  You could probably use a box with a smooth bottom.  I also thought later that a box with a clear top could be useful, too, just to be able to look in and read the Victron.

I bought a stack of cable glands because I had no idea how they worked.  The Tab's original ring terminals were too small to fit the shunt so I had replaced them.  I didn't want to replace them again, so I had to use a larger gland nut that would pass the wires with the ring terminals in place.  If you see you need to re-crimp some new terminals to attach to the shunt, work the gland nut into position on your box with the unterminated wires through it and you can use a smaller nut and probably better watertight seal.  I used the PG16 gland for them.

I have discovered a lot of different uses for the cable glands, especially for strain relief on other wire projects, such as the solar panel, etc. So it wasn't a total waste for one gland!

https://www.amazon.com/gp/product/B07GJDYGP5/ref=ppx_yo_dt_b_asin_title_o03_s00?ie=UTF8&psc=1

I needed a longer and more flexible negative battery cable.  3ft, easy to deal with, 18 bucks. ( I don't know if that is a good price, but it was an Amazon thing.)

https://www.amazon.com/gp/product/B01DRFRFP2/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1

The gland nut size for the terminals on the battery cable turned out to be PG19, so I bought a few of those.  The gland nut sealed around the cable just fine, but there were still spots that needed to be sealed around the nut and the case.

I learned a lot (gland nuts!)   As I said, if you do this, you can probably get a better fit with unterminated wires going through the case and the nuts.  I wasn't familiar with how exactly the nuts worked, so, practice.  If you are good at drilling through plastic you can probably find a blank box and drill the exact sized holes that would seal correctly.

Photomom

The thing I really like about these solutions is they do not permanently alter the T@B.