Installing a Victron BMV-712 (1 Viewer)

[Sportsnapper]

I've searched and read every thread in the last few years that mentions a BMV-xxx, but still have a few questions on how I actually install the physical device in the van - and Exsis 578. I'm happy with the wiring, but it's locating the shunt, and probably a busbar (see https://www.motorhomefun.co.uk/forum/threads/victron-bmv700-installation.174863/#post-2826383) for the negative connections that I'm struggling with. I'm decided to use the busbar when I discovered that the Victron shunt has M10 connections, and all the other battery connection are M6 - so rather than remaking them, which I don't have correct tools to do, it would be simpler to put a busbar in. 12vplanet will then make up leads for me in the correct length and with the right connectors.

The batteries are located at the side of the seat in the Exsis, and there's not a lot of room. Just tidying up the installation gives more space in front of the batteries, and I think that the shunt and busbar could be screwed into the wood - though it would cover up a sticker that indicates the fuse connections on the side - see images below. There's also not a lot of room to do anything!

Other ideas are to mount the shunt on a piece of wood and mount that vertically in the space. Or screw them to this piece of wall - though I'm not confident about screwing into the main wall of the van - unless someone can tell me how thick it is and that it won't subsequently cause an issue with damp etc.

The BMV-712 has a facility for monitoring a second battery, and I would like to be able to monitor the vehice battery. The wiring diagram shows a complete second set of connections

I'm not sure how I can connect the shunt to the vehicle battery. Can I connect the +ve cable to the +ve starter battery connection in the rear of the EBL (EBL29)? What about the negative - is there a direct connection from the battery that comes into the Hab area that I can use - or am I running wires and drilling holes.

<aside>This is what my Father called a "Just job" - ie just install a battery monitor. Much more difficult than it appears</aside>

Finding an appropriate home for the Meter is another issue that I've not tackled yet. And yes, it's got Bluetooth but it's a lot easier to press a button quickly sometimes.

 

[Lenny HB]

I fitted one of these to the shunt.

Finding an appropriate home for the Meter is another issue that I've not tackled yet.

I replaced one of the mains sockets on my DL with the BM700.

 

[andy63]

I'm not sure how I can connect the shunt to the vehicle battery.

Just reading your thread and cant help with the location for your shunt..
It does look tight..from the photos but they dont take up a lot of room as long as the heavy wires are made up to size ..
Your question about connecting the second or start battery is confusing me...
Ive fitted a couple of these type of monitors but not your one , and if you need full monitoring on another battery (ie current flow , rather than just voltage readings )do you not need a seperate shunt on that battery.?
If you are just happy to monitor voltages then the wires required are small and could be taken from any point in the system that is connected to the battery in question, but direct to battery may be better if the other points are a distance from the battery..
Andy.

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[Infinity31]

Can't help on the location side of things but I recently fitted Viltron BM with the connection to monitor the voltage of the starter battery.

I only had to connect the fused supply cable from B2 on the shunt to positive on the starter battery as the negatives of both starter and habitation are common.

 

[Sportsnapper]

Thanks, guys.

@Lenny HB - Thanks - any idea what that type of connector is called - seems an easy solution but I've tried searching to no avail. And yes, I saw your previous post remounting in an unused 13amp socket, but not possible in the Exsis as the spare ones are part of two or three gang plates with switches. I also saw a post of yours that suggested that sometimes there were panels which had semi-cut positions for later socket addition, and I need to search for one of these. I've found one near the upper fridge vent, but it comes out above the sink on the RHS, and it's not a great position for a monitor. I also wondered about the panel above the TEcTower oven but worried it may be a bit hot for the device.

@andy63 @Infinity31 - thanks - only looking to monitor voltage, so your answers confirm my thinking. I did have in my notes about the common negatives, but it got missed from the post. I'll connect the positive to the back of the EBL as that may be easiest.

 

[Lenny HB]

Thanks - any idea what that type of connector is called

BM5143 Ring terminal, they come in various sizes 10mm, 8mm & 6mm. Where I got mine from (ebay supplier) not showing any stock of the 10mm at the moment.

I also wondered about the panel above the TEcTower oven but worried it may be a bit hot for the device.

Don't even go there, gets far too hot.

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[Sportsnapper]

I'll keep looking for a location!
Found more BM5143's on ebay, so ordered the cheapest

 

[karalal]

To monitor the starter battery you will need a cable from the negative post to the shunt and the supplied thin red cable from the positive post of the starter battery to the connector on the shunt marked b2 on the diagram

 

[Pausim]

To monitor the starter battery you will need a cable from the negative post to the shunt and the supplied thin red cable from the positive post of the starter battery to the connector on the shunt marked b2 on the diagram

I can’t see how one shunt can monitor both habitation and starter battery.

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[Sportsnapper]

It can't, but all the second battery monitor check sis the voltage, none of the "fancy" stuff AFAIK.

I only had to connect the fused supply cable from B2 on the shunt to positive on the starter battery as the negatives of both starter and habitation are common.

I guess if it works for @Infinity31 then it should work for me. If it doesn't watch this space

 

[Infinity31]

It can't, but all the second battery monitor check sis the voltage, none of the "fancy" stuff AFAIK.



I guess if it works for @Infinity31 then it should work for me. If it doesn't watch this space

If the negatives weren't connected prior to fitting the monitor then the habitation batteries wouldn't charge from the alternator with the engine running.

So when you connect the habitation negative to the shunt you are connecting the starter negative also. You only need connect the positive

Yes, It only measures the voltage and none of the 'fancy' stuff

 

[Sportsnapper]

That was meant to be a light-hearted reposte - I'd worked out the logic of the common negatives, but needed to ask the question earlier to validate my thinking. Once you said you'd done it I was happy that it's all going to be fine - hopefully by the weekend! Nice profile pic BTW

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[Infinity31]

Yep I realise that, I posted in response to other comments just to reiterate the point

Lets hope it works

Thanks, Pic was taken on a trip to the Western Isles a few years ago, one of the very few times it wasn't raining and blowing a gale. A rare glimpse of sun and blue sky.

 

[two]

I put the shunt onto a separate piece of MDF that I had spare. I shaped it to fit where it would be convenient to fit, then wired it up before screwing it in place.
I did a bit more than just add the shunt. I added a fuse and isolation switch for an inverter and then +ve & -ve distribution points for various extras. Yours is likely to be simpler.

Whilst the BMV can monitor the voltage of a second battery (starter) it will not measure the remaining capacity (Ah). I chose to get the temperature sensor instead.

 

[Lenny HB]

I'll keep looking for a location!
Found more BM5143's on ebay, so ordered the cheapest

Cheapest not always best as long as it's copper or brass should be OK a lot of cheap connectors poor quality alloys that don't conduct very well.

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[Sportsnapper]

@rogher Yep, I saw this in one of your earlier posts, and wondered about doing this but there's not really room for a board. I'm planning to screw the shunt to the floor of the battery chamber and use the connector @Lenny HB pointed out above. Same for the fuse that I need to add to my inverter installation. BTW the woring diagram in your post was very useful

 

[Lenny HB]

In my Exsis I mounted the shunt on a piece of R/A aluminium fixed to the side of the battery box.

 

[Sportsnapper]

Update on progress!
Eventually, my cheap BM5143 turned up from ebay, so I was able to proceed with the installation (1st class post and it still took 3 days from when they said they'd sent it) - it was copper and quite nicely made.

I decided to mount the shunt on the aluminium angle on the side of the battery box - as @Lenny HB suggested, giving much better access to the shunt in case I needed to modify the wiring at any point. Originally it was going to be at bolted to the vertical part (hidden in the images). To drill the holes I removed the battery, then realised that it was going to be easier to mount it upside down under the aluminium angle. Mounted the shunt, wired it up, and then replaced the batteries (breaking one of the vent plugs in the process ).

plugged in the monitor, and it didn't power up. Checked everything, and plugged the monitor in again. Nothing. Took the inline fuse out of the positive wire (dropped it - it's n the van somewhere, no idea where) and replaced it with the one from the other positive feed. Plugged the monitor in and it lit up. I then did the setup via Bluetooth, and alls well.
Next step was to wire the second positive wire to the Starter battery. I looked at taking the +ve feed from the Schaudt AD-01, which is under the seat by the batteries. But there's no spare +ve feed, and I didn't want to mangle any of the connectors to create a connection. Then a eureka moment - the starter battery is in the cab - not in the engine bay (New van to us - not used to having the battery inboard!). So the positive for the starter is attached to the main terminal and routed under the floor ( another "just" job ). Plugged it into the shunt, and like magic, we also have the Starter battery voltage on the display and in the app with no need to mees about with any -ve connection.

The next step is to find a location for the battery monitor itself (as opposed to shut up in the battery compartment as it is at the moment). Two candidates, one is to move the pump on/off switch from its location by the control panel (why does it exist- never had one on our 2005 Hymer) to the side of the kitchen drawers and mount the Victron in its place. The second option is to just mount the Victron on the side of the kitchen drawers.

The first option means routing the cable up to the control panel (presumably under the door, into the drawer space, then up through the furniture to the control panel), and doing the opposite for the switch. The second option, which is simple, just means routing the cable to the drawer space (shown) and drilling a hole - unfortunately it's where the black panel currently is in the image. Anda third option os to remove the 12v socket/TV connection from behind the grey cover and position it there. We don't use the TV socket (and there's also a status aerial wire run out to that panel as well1) - but it is the one and only 12v socket in the van (thanks Hymer) so a new one would need to be fitted somewhere.

Long post - hopefully helpful to someone in the future, and also a way of me working out the options for the monitor location by writing it down.

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[Lenny HB]

It is quite easy to get the cable beside the kitchen fed into the back of kitchen draws via a hole through the floor. Probably worth investing in a set of short threading rods they save a lot of time.
Water pump switch saves you burning out the pump when you have the system drained down, been there done that.

 

[Pausim]

The next step is to find a location for the battery monitor itself (as opposed to shut up in the battery compartment as it is at the moment).

I have left my monitor in the battery compartment and just use the Bluetooth app to keep an eye on things.

 

[two]

The display would need to be at eye level to serve a useful purpose, although not necessary at all if you have the bluetooth module. Remember that the cable to the monitor has a RJ(12?) connector that needs to be drawn though any constrictions that may exist.

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[Lenny HB]

RJ(12?)

RJ11

 

[Sportsnapper]

Water pump switch saves you burning out the pump when you have the system drained down, been there done that

- Ah - we don't ever drain our system down as we use the van over the winter for cycling or extra accommodation. But I see your point!

I have left my monitor in the battery compartment and just use the Bluetooth app to keep an eye on things.

Short term this is fine, but Mrs Sportsnapper likes pushing the buttons!

The display would need to be at eye level to serve a useful purpose, although not necessary at all if you have the bluetooth module. Remember that the cable to the monitor has a RJ(12?) connector that needs to be drawn though any constrictions that may exist.

Side of the drawer unit could be OK - it's almost eye level when you enter the van!

I don't think the Rj11 will be a problem, it's only just bigger than the cable - and I can always re-make the end.

I'm quite keen to replace our twin Truma dials with the CP+, but I don't think it will fit over the existing fittings (see earlier image). I'm now looking at an alternative option of moving the water pump switch and my new Victron Battery monitor gauge into the position the Truma controls occupy and then putting the CP+ where the pump switch is. Shouldn't be any holes then!

 

[Lenny HB]

I'm quite keen to replace our twin Truma dials with the CP+, but I don't think it will fit over the existing fittings (see earlier image).

I did that in my Exsis but I only had one dial (gas only). You could fit a bushed anodised aluminium panel I did that with a cheap battery monitor I fitted to my Exsis it looked good. Can get the alloy cut to size for a couple of quid on eBay. Fixed the panel with very strong thin self adhesive tape.

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