Installing Victron BMV-712 T@B 400 2019

Davids

Hi , this is my first post, but I want to saying since we bought our trailer I have found the information on this forum very helpful.
I am installing the BMV-712 into our T@B 400 in contrast to some other years/models our batteries are covered by a plastic cover, with many screws. In reading the posts it sounds like people with the 2019 model have installed the BMV-712 without removing the plastic cover and accessing the battery. But I was unable to find how this was done, can anyone who has done this share their experience with me? 
Also I did succeeded in getting the venting pipe off of the plastic cover. While I have not tried yet, I think I could remove the plastic cover, would this be a better option? 
I have included a picture showing the layout from NuCamp, any advice is appreciated. 
Thanks

Denny16

This could be simple, no need to remove the battery cover.  See the Red and White wires coming from the battery box to the little square box next to it.  The Red wire is positive and the white wire is your negative connections.  The little black box they go to is a two pole distribution unit.  You can remove the cover on this small black box and under it you will find two posts, one with the whole wire and one with the red wire.  

Mount your Battery Monitor Shunt next to the distribution box, so the white wire from the battery can attach to the battery side of the shunt.  Next you will need a new No 4 gauge battery jumper wire to go from the load side of the shunt to this post where the white wire used to go.  This will put the entire trailer system load on the Shunt.  Next Connect the positive shunt wire to the post the red wire is attached, think of this as your battery positive connection. Locate the display where you want, and plug that into the shunt, and Bob’s your uncle...
cheers 

Sharon_is_SAM

@Denny16 - there is an inverter, no?  Does the inverter negative lead need to be relocated?

falcon1970

@Davids
Removing the rubberized/plastic cover from the battery is not difficult but it is "fiddly."  There are numerous screws along the flange at the bottom and several across the top where nuCamp cut the flange away.  The battery vent is held in place by a common hose type clamp and like all those hose clamps it is awkward to loosen the clamp.  You will have to fiddle with the duct to get it off of the rubber cover--and to get it back on later.  The fittings around the wires from the battery can be loosened and pulled away enough so that you can maneuver the rubber battery cover out of the way.  The wires from the Victron can be pushed through the existing fittings for the battery wires--there is plenty of room.  You may also have to remove the wire brackets so the wire running along the rear bottom of the case can be moved.  You don't need to disconnect that wire from anything.  Just move it enough so you can move the battery case.
Pay attention to what screws came from where and reassembly is fairly straightforward.  Except you probably won't be able to put all the screws back in the same hole from which they came.  Not a problem as long as you get everything snugged back down.
As I said, it is not hard but it is a bit aggravating.

Denny16

Sharon, yes, the inverter needs to go to the shunt.  I edited my previous post, using the distribution box negative post to the load side of the Shunt.  So,what you are actually doing is putting the shunt between the battery and it’s former connection on the small distribution box.  

The way the battery cables are connected to the sealed box through the water proof wire gland bits, means you would need to cut the negative wire crimp off on the battery side, and re crimp a new post connector to connect it to the load side of the shunt, and make up a new cable to go through the water proof gland box, then crimp another battery post connector to it.  If you have a no. 4 wire crimp this is an option.  

However if not, my original suggestion to leave the battery box, and put the shunt between the battery white cable and the distribution box is easier all round.  This way only a new No 4 jumper cable is needed and can be purchased with the necessary crimp ends already installed.  This is the easiest way to add in the Battery Monitor in this situation.  All the trailer load connections on the distribution box will now be on the load side of the Shunt without a lot of rewiring required.
cheers

Sharon_is_SAM

@Davids

https://tab-rv.vanillacommunity.com/discussion/9261/new-victron-monitor-installation

https://tab-rv.vanillacommunity.com/discussion/8438/shunt-location-2019-tab-400

https://tab-rv.vanillacommunity.com/discussion/7659/wiring-questions-for-2019-t-b-400

https://tab-rv.vanillacommunity.com/discussion/10087/2019-tab-400-battery-access

Davids

Denny, Sharon, Falcon thank you for your responses I will get back to you if I have any more questions once I have time to go through all of this. 

TNOutback

The only reason to remove the battery cover is if you have the version of the BMV with the temperature sensor, which would be placed on the positive battery post to sense the battery’s temperature.

falcon1970

True what @TNOutback said.  If no temp sensor then it is as easy as @Denny16 said.

Denny16

The temp sensor is optional anyway, nice to have but not mandatory.
cheers

Davids

Again I much appreciate the advice. 

@Denny16 can you confirm that I am understanding you correctly and that I can just route the existing negative going into the two pole distribution unit to the new shunt, and then run a new negative wire from the shunt back to the distribution unit. Just wanted to confirm, since I do have the invertor and your response back to Sharon confused me abit, since my electrical knowledge is very limited.

Looking at the other posts Sharon included, it sounds like the new negative wire I require should be 1/0 wire, with terminal studs that are 3/8" - is that correct?

And can someone tell me what the benefits of getting the temp sensor would be?

Denny16

With the Inverter that should work fine.  Always better to go bigger than smaller.
Yes, just move the battery wire to the shunt, and then connect the load side of the shunt to the battery distribution box where the battery was connected is correct.  Turn off the battery cutoff switch, and if you have solar  on the roof, cover the panels or make the connection after dark, or just turn off the solar charging from the Victron phone app.

This will drop any load on the distribution box, as the positive is still connected, so I would cover the positive post with electrical tape first to prevent an accidental short.  You can touch one battery terminal at a time, but do not want to short them or touch both at the same time.  Not much voltage but a lot of current (amps).
cheers

Davids

Thanks Denny I was going to ask about that, do you mind telling me the difference between volts and amps?

Denny16

Here you go: https://www.thespruce.com/amperage-not-voltage-kills-1152476
cheers.

JCALD

Anyone with the BMV-712 monitoring the midpoint voltage where you have two 6 volt batteries in series supplying 12 volts?  Wondering if it is worth doing.  I plan to install a Bluetooth temp monitor when we go Victron solar.