I now considering installing the shunt inside but I have no idea how I should pass the cable though the floor. Considering that the floor is composed of many layers of different material, I suppose you can't simply use a grommet.
The multiple layers can certainly be an issue. It is kind of a crude way, but I usually will cut a hole that is a bigger than the cable and then use a couple of layers of the split wiring sleeving over the cable(s). Size the opening to allow for the sleeving. You will probably have two cables in sleeving, so I would do them individually sleeved or the sleeving will need to be very large.
Once you have the wiring all done, you can use silicone sealant from the top and bottom to fill all around the wiring, completely seal the opening, and even a bit above the floor surfaces to get a little extra strain relief. You do still need to make the cabling is restrained well so it won't bounce separately, though.
Be sure to check for wiring where you are going to drill. It is not uncommon for their to be some wiring between the van floor and interior plywood floor, in the recesses of the van floor.
Perhaps you could find a cable gland/grip long enough for your floor, or use PVC conduit. I used aluminum for the penetration on the roof for solar panels and another one for the shore power cable.
I mounted my shunt in a short length of CPVC drain pipe and used 2 end caps to seal it. That way I was able to mount it inside the battery drawer without any danger of damage from battery fumes or the environmental hazards. The shunt does heat up in use but the power generated is 5 watts at 100 amps for a 50mV shunt (7.5 watts for a 75mV). This did not appear to me to be much of a problem and so far it has created no issues.
I mounted my shunt in a short length of CPVC drain pipe and used 2 end caps to seal it. That way I was able to mount it inside the battery drawer without any danger of damage from battery fumes or the environmental hazards. The shunt does heat up in use but the power generated is 5 watts at 100 amps for a 50mV shunt (7.5 watts for a 75mV). This did not appear to me to be much of a problem and so far it has created no issues.
Your van should have an AGM battery, so there will be no fumes unless something goes wrong with the battery or charging, and you would know that long before the shunt got damaged.
With no fumes, if it is a relatively clean area, I think I would drill some holes through the pipe to get a bit of air through it, even at 5 watts.
I now considering installing the shunt inside but I have no idea how I should pass the cable though the floor. Considering that the floor is composed of many layers of different material, I suppose you can't simply use a grommet.
I'm planning on doing the same thing (new ground cable with termination inside) I will get a new, longer ground cable and just follow the positive cable, along its route. Using the shielding and hangers where possible.
Where the positive enters the coach, so will I.
Not sure if I will run a new positive cable at the same time.
I received my Victron battery monitor but I do not stop to change my mind about whether I will install it or not... It very cold outside and all RV shops in my area are closed for the winter. So if something goes wrong, I could jeopardize
our trip.
One "issue", is that the cable from the battery has 5/16" ring terminal but the shunt has 3/8" bolt. My plan is to use the Dremel with a sand paper band to enlarge the terminal. Sounds good?
The other things is that there is a unknow red product on the chassis connection and I'm afraid this stuff could prevent a good contact when I will reconnect the terminal. How could I clean them?
We had the same issue with ours, so when I redid our power system I did bring all the negatives, including chassis, to the shunt inside the van.
Reviving an old thread here but I am also deciding on a location for a shunt. I can see that bringing all the grounds to the shunt with good wiring would help eliminate any ground resistance that would throw the accuracy off. I guess I may not understand how the shunt works but is running all the grounds to the shunt absolutely necessary if you make sure the chassis grounds are in good shape?
Reviving an old thread here but I am also deciding on a location for a shunt. I can see that bringing all the grounds to the shunt with good wiring would help eliminate any ground resistance that would throw the accuracy off. I guess I may not understand how the shunt works but is running all the grounds to the shunt absolutely necessary if you make sure the chassis grounds are in good shape?
Current flow has to pass through the shunt to be seen by the shunt. The current from any circuit that bypasses the shunt won't be measured.
I can see that bringing all the grounds to the shunt with good wiring would help eliminate any ground resistance that would throw the accuracy off. I guess I may not understand how the shunt works but is running all the grounds to the shunt absolutely necessary if you make sure the chassis grounds are in good shape?
On the contrary, a proper chassis ground is SUPERIOR to running return wires. This is true in two ways:
1) The ampacity of the chassis is huge--much greater than wires of any practical size.
2) Running ground wires risks the creation of ground loops, which can cause problems with electronics--especially audio hum. This happens because many devices already have inherent chassis grounds and adding a second one causes an undesirable loop.
The problem is that creating a good chassis ground is not always easy. Best to always use the engineered factory-designated ground points.
Note also that a bad ground will NOT effect the "accuracy" of a shunt. As long as the shunt is the only path to the battery negative, the shunt will measure all current that flows. A bad ground may increase the circuit resistance and thus lower the current in the circuit, but that lower current will be properly measured.
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Now: 2022 Fully-custom buildout (Ford Transit EcoBoost AWD)
Formerly: 2005 Airstream Interstate (Sprinter 2500 T1N)
2014 Great West Vans Legend SE (Sprinter 3500 NCV3 I4)
I am in process of installing a battery monitor on my RT Adventurous. I was able to economize some space on the control panel area for the display, and relocated the water heater controls next to the Inverter control switch.
Getting the control wire from the display back to the shunt is a challenge. Have not yet found an easy path behind all the plastic in the bathroom. Will add more info when I crack that nut.
I pulled the two negative cables back into the electrical compartment accessed from inside the vehicle, and located the Shunt on the back wall. The charging line is 6 ga and the ground line is 2 ga. I was able to run the existing 2 ga ground line from its grounding point through a new hole and to the load side of the shunt. I also used about 10" of the 6 ga to connect from the load side directly to the negative side of the charger/inverter. I required a new 6' length of 2 ga that was about $32 on amazon (with lugs) to run from the battery side of the shunt to the battery negative. I put this new line in a protective sleeve like the other exterior wiring uses.
Picture of shunt location and display are provided. I left enough room for a future solar charge controller (which also has a remote display/control that will also go up by the other controls).
To clarify, the two connections shown are on the load side of the shunt, the 6 ga from the charger/inverter going to the left, and the 2 ga to vehicle ground leading downward. The Battery side is unconnected (waiting on new 2 ga cable).
I figured out a routing that required two holes to be cut but leaves plenty of room for eventual solar installation.
From the control panel I drop the line down the space that contains the tank vent. The first hole is right below the horizontal structural member, behind the passenger seat. I will cover this hole with a round access plug or decorative electrical box cover.
The second hole is through the fiberglass panel in the bathroom, about the same height as the first hole and behind the sink plumbing access cover. It is a straight easy shot from the first hole. It also provides a place to clamp down the cables passing through. When the access panel is replaced everything is out of sight. From there I drop the wire out and back in the existing plumbing cutout, which goes almost directly into the water pump space and electrical space.
Yes, heat is an issue as a shunt is just a very low resistance resistor. There have been several discussions that I have seen over the years that had different opinions on how hot the shunt would get in a sealed box anywhere, including under the van. The specs usually say something like not to run a shunt continuously at more than something like 70% rated amps because of heat buildup.
The BMV-700H comes with a shunt box so I'm now wondering if power dissipation is really a problem at all. I know the shunt could dissipate up to 25W but maybe all the heat will dissipate in the cables? Copper has a high thermal conductivity.
Thanks for the picture of the Victron shunt box. Renogy has a great shunt/monitor for about half price of the Victron, but they come without a box (big oversight). I purchased something very similar and drilled a couple of holes through it, not knowing what Victron uses.
The Renogy is rated at 500 amps, although I'll probabably never draw even a fourth of that. Hoping heat is a non-factor.
Thanks for the picture of the Victron shunt box. Renogy has a great shunt/monitor for about half price of the Victron, but they come without a box (big oversight). I purchased something very similar and drilled a couple of holes through it, not knowing what Victron uses.
The Renogy is rated at 500 amps, although I'll probabably never draw even a fourth of that. Hoping heat is a non-factor.
The heat thing with shunts is really very short on good information, I think.
The rate shunts for capacity, but that is normally the maximum capacity they can pass through them, not continuous. They then add disclaimers about not using the shunt at more than 60 or 70% of rated but put no time limit on how long they can handle more throughput. Always notes about using in well ventilated ares, but then sell you a box to put it in.
What's the point of putting this 'heat generator' in a box?
Well, for protection of the terminals for one thing. Without a box (due to my confined space) it would rest directly on the metal top of my inverter/charger. But no reason the box couldn't be ventilated.
My box has a clear hinged top with latch. I guess the next time I'm charging at a high rate or stress testing the inverter output, I'll feel the box and also flip it open and also give the shunt a feel for any heat buildup.
I guess the next time I'm charging at a high rate or stress testing the inverter output, I'll feel the box and also flip it open and also give the shunt a feel for any heat buildup.
Guess we'd never considered that we could heat our van with the shunt until this thread! We actually installed a second shunt but fortunately both are in positions where 'box protection' isn't necessary.
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2016 159" High Top DIY ProMaster with 500ah Starlight Solar/Elite LiFePo4, 930 watts Hyundai Solar w/MidNite Solar Classic MPPT, Magnum 2812/MMP250-60S Charger/PSW w/remote, Nations 280amp 2nd Alternator with DIY [formerly, Balmar] regulator, NovaCool R4500 12/120v frig, 2 burner TruInduction cookstop, SMEV 8005 sink, FloJet R4426143 pump. No A/C or indoor washroom.
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