More questions than answers.

bergger · April 2020

Since taking possession of our 2021 T@b 400 last month she has spent her time sitting in the storage lot. Hopefully we will get her out for the maiden voyage soon. Well today we paid her a visit to move some stuff in and organize things. I spent some time poking around and trying things out. We have the roof mounted solar system and had the BMV-712 monitor added along with a Zamp exterior solar plug. I have a few questions of the electrical nature I need help answering as I do not understand this stuff very well.

It was overcast today and the solar panels were generating between 7-80 watts of power depending on the cloud cover. I decided to plug in our Go Power 80 watt solar suitcase to see how much it would assist the factory system. I do not understand the results I got. When I plugged in the suitcase the solar watts, solar current and battery current all dropped to 0 while the solar and battery voltages increased. When I unplugged the suitcase it all reversed. I was expecting to see all the numbers increase, especially the solar watts and current. With the voltage increase it appears to be generating something. So first question is, why did this happen? I used the correct adapter to adjust for the zamp reverse polarity which then went into the anderson plug of the suitcase.

I then decided to turn on the norcold 3-way fridge on 12v just to see the draw it had on the battery. I brought up the BMV-712 app and the voltage immediately dropped when the fridge was turned on but the current, power and consumed Ah all remained at 0. I would have expected the current and power to have an immediate negative number. I also turned on the inverter and had the same results. When I turned them off the battery voltage immediatley climbed back up. So why these readings? The app does have the proper battery settings entered. Are there any other settings I need to adjust?

The last question is hopefully the easiest. What is this junction box in the passenger side storage compartment?

I've attached some photos of the readings I had and of the junction box. Sorry for all the questions as I can usually figure things out myself but this electrical/solar stuff in not in my wheel house. Any input would be appreciated.

jkjenn · April 2020

Tell us a little more about your tour solar setup. A couple of thoughts of where to start troubleshooting:

Do you know for sure that the Zamp port is connected to your SmartSolar controller?

You are running different voltages with your roof mount and your 80 watt panel. That could cause issues.

The Zamp port uses a reversed polarity. The Victorn also reverses polarity in the controller. You might need to swap the wires.

pthomas745 · April 2020

How many amp hours in your battery bank? How long did you run the fridge on 12V? It could be that your full battery and strong solar input for a short period of time just didn't register for amp hour use on the Victron. You should have seen the current being used change, however.

The voltage number will always change if the battery is under load. The change from 13.90 to 12.58 when you turned on the fridge is normal.

The Gloso box is a 40 amp circuit breaker for the battery. In this thread, where an owner apparently had a problem with it, there is a discussion of what it is.

https://tab-rv.vanillacommunity.com/discussion/comment/93814#Comment_93814

bergger · April 2020

Thanks for the responses. It's a 224 amp hour dual 6 volt set up. Maybe I did not have the fridge on long enough to not have a drop in the Ah reading. However I would expect the others to show the draw. Need to figure out why that is not happening. It may be like Jkjenn mentioned. Maybe the Zamp plug is not run through the smart solar controller and thus not reading the input from it. It may be charging the battery but not being read by the solar controller? The suitcase does have it's own controller so that may be the case. And thanks for explaining the Gloso Box! I'll have to get out there this week and look at it more to try figure it out.

TNOutback · April 2020

My Victron solar controller will display zero when I am plugged into shore power. Also, power consumption is time-based, so AH consumption is not an instantaneous reading.

bergger · April 2020

TNOutback said:

My Victron solar controller will display zero when I am plugged into shore power. Also, power consumption is time-based, so AH consumption is not an instantaneous reading.

So do you think when I plug in my solar suitcase it's reading 0 just as if it's plugged into shore power? When plugged into shore power and the battery is being charged by the converter is it still gaining a solar charge or is that interrupted and in essence shut off?

And thanks for the input on the Ah reading. However still not sure why the bmv-712 is not showing the power draw from the fridge or inverter running. Not sure how I'll figure that out.

Also, would the zamp plug normally be wired directly to the battery or would they wire it somehow to the smart solar controller? I'm going to try to open it up this week and look at it and see if I can figure that part out. If it's wired directly to the battery, since the suitcase has it's own controller I'm assuming it would work just fine and independent from the roof solar. But the 0 watts reading from the roof top makes me question that theory.

My portable suitcase is 80 watts with a 10 amp controller.

Tundra57 · April 2020

Just an fyi. I have a Victron MMPT 75/15 controller powered by the factory panels. Unless the battery is fully charged or on shore power there is always a little current to the battery. If I turn anything 12v on when no shore power the current goes up.

I added a 200 w solar suitcase. But I have a second Victron controller also connected to the battery. The solar panel connector is also on the outside of the Tab.

When I connect the external solar panel too, both panels supply current. The sharing depends on which panel has most sun.

Both controller s are MPPT which are more efficient that the cheaper versions.

Also note: my external panels setup has diodes inside each panel. This prevents the lower voltage panel trying to circulate current in the higher one when the sun is not the same on both.

Now if you are trying to parallel the external panels with the tab panels using the same controller, you could just be circulating current in the lower voltage panel, or the external panels could be lower voltage so cannot push current into the controller. The best way I found is for your external panels to have their own controller (some have them built in) and the solar connector is just fused to the battery.

As before mentioned, make sure the polarity is correct.

bergger · April 2020

So I had just a little time today to poke around the trailer again. I was able to confirm that the Zamp plug NuCamp installed is connected directly to the dual 6v batteries. My go power 80 watt suitcase has it's own built in 10 amp controller. So I assume it will assist in charging the batteries at the same time the roof solar is. Still not sure why the roof solar app goes down to 0 watts when the suitcase is plugged in? But hopefully both solar systems are charging the batteries.

But again more questions than answers. Not sure if these next questions have anything to do with my question above or not. So I opened up the compartments under the bed to confirm the Zamp wired directly to the dual 6v batteries. I then looked at the Victron BMV-712 shunt I had installed at the NuCamp factory when the trailer was built. I'm not sure they did it right! Unfortunately I did not have my phone to take a picture but I took notes and drew a picture of what I saw. I'll get a photo graph of the set up tomorrow.

The shunt has the data cable coming out and going to the monitor, which is good. The rest i'm not so sure about. There are then two red wires +B1 and +B2 both connected to the main positive terminal of the batteries and the shunt. I believe there should only be +B1 connected since I do not have a separate battery to monitor such as an aux battery or starter battery. Would this cause an issue having both plugged in? It would certainly explain why I see aux battery as a reading when I cycle through the display.

Then there is a heavy gray wire going from the main negative terminal of the battery bank to the "Load + Charger" terminal on the shunt. The "battery only" terminal on the shunt has nothing attached to it! From my limited reading and research I believe this may be incorrect. Should'nt there be a battery cable connected between the main negative terminal of the battery to the "battery only" terminal on the shunt not the "Load + Charger" terminal. And there should be another battery cable from the "load + Charger" terminal of the shunt to somewhere else in the trailer (maybe the main distribution box)?

So does it appear that it was wired incorrectly? Should I disconnect/remove +B2 wire completely, connect the main negative terminal of the battery bank to the "battery only" terminal on the shunt, and then run a wire from the "load + Charger" terminal on the shunt to someplace in the trailer? Not sure where that connects to.

I'll get a picture tomorrow of what it looks like before I do anything. Any thoughts would help.

Cbusguy · April 2020

That sounds backward but please send pictures.

B1 should go to the trailer battery......b2 is used to monitor the starting battery if applicable.

Depends on how you connect the suitcase....first beaware that the zamp plug is not industry standard polarity....get a volt meter and verify the polarity on your suit case matches the zamp polarity.

pthomas745 · April 2020

+1 on the SAE connector (the "zamp plug") on the trailer. What do you use to connect your GoPower to the SAE? If you haven't wired it correctly, it could be an issue. Long story short: that big metal part of the SAE cable should be wired to the negative side of the solar controller output to the battery. ("Should" is the key word here: check the trailer's plug with a voltmeter.)

jkjenn · April 2020

bergger said:

So I had just a little time today to poke around the trailer again. I was able to confirm that the Zamp plug NuCamp installed is connected directly to the dual 6v batteries. My go power 80 watt suitcase has it's own built in 10 amp controller. So I assume it will assist in charging the batteries at the same time the roof solar is. Still not sure why the roof solar app goes down to 0 watts when the suitcase is plugged in? But hopefully both solar systems are charging the batteries.

But again more questions than answers. Not sure if these next questions have anything to do with my question above or not. So I opened up the compartments under the bed to confirm the Zamp wired directly to the dual 6v batteries. I then looked at the Victron BMV-712 shunt I had installed at the NuCamp factory when the trailer was built. I'm not sure they did it right! Unfortunately I did not have my phone to take a picture but I took notes and drew a picture of what I saw. I'll get a photo graph of the set up tomorrow.

The shunt has the data cable coming out and going to the monitor, which is good. The rest i'm not so sure about. There are then two red wires +B1 and +B2 both connected to the main positive terminal of the batteries and the shunt. I believe there should only be +B1 connected since I do not have a separate battery to monitor such as an aux battery or starter battery. Would this cause an issue having both plugged in? It would certainly explain why I see aux battery as a reading when I cycle through the display.

Then there is a heavy gray wire going from the main negative terminal of the battery bank to the "Load + Charger" terminal on the shunt. The "battery only" terminal on the shunt has nothing attached to it! From my limited reading and research I believe this may be incorrect. Should'nt there be a battery cable connected between the main negative terminal of the battery to the "battery only" terminal on the shunt not the "Load + Charger" terminal. And there should be another battery cable from the "load + Charger" terminal of the shunt to somewhere else in the trailer (maybe the main distribution box)?

So does it appear that it was wired incorrectly? Should I disconnect/remove +B2 wire completely, connect the main negative terminal of the battery bank to the "battery only" terminal on the shunt, and then run a wire from the "load + Charger" terminal on the shunt to someplace in the trailer? Not sure where that connects to.

I'll get a picture tomorrow of what it looks like before I do anything. Any thoughts would help.

I would email tech support at nüCamp. That doesn't sound right. They might direct your to repair because things like the Victron are done through repair after the unit is produced.

Tundra57 · April 2020

The shunt needs to be in series with the leads to be measured. What do you want to measure with the shunt? If you connect one of the chargers directly to the battery and it misses out the shunt then you will not measure its current. The second battery plus lead may be connected to measure the mid point if you have two batteries in series so you can see if the batteries are balanced. So try and draw out where your connections with pictures if poss abd then we can help you out more easily.

Denny16 · April 2020

There are two types of second connections on the shut for the positive two small red wires. If both red wires are on s common battery connector, then the second wire is a battery temp sensor wire, which is what mine has. If the two red wires each have their own connector, then the second one is for mid point or second starter battery connection.

One end of the shunt is connected to the battery negative terminal, and all the previous negative battery connections are on the other side of the shunt (battery distribution box, etc.
cheers

ChanW · April 2020

You're right.
The large 'Battery' terminal on the shunt goes to the negative battery terminal.
The large 'Load' terminal on the shunt goes to the Tab's negative battery cable (and anything else that would be normally connected to the negative battery terminal).
So what is connected to your negative battery terminal now? All 'loads' that normally connect to the battery negative terminal, should be connected to the shunt 'load' terminal. That includes the Zamp wire.
Also, you're correct about the +B2 wire. Remove it.
Also, as others have said, contact Nucamp about it, in case it becomes a warranty issue.

bergger · April 2020

I opened things up this morning and got some photos. I do believe NuCamp may have not connected things properly. However with my extremely limited understanding of electical things I'd like you opinions. I've attached a photo of the overall set up and the shunt as they came wired from the factory. The main distribution box is on the other side of the wall on the left side of the photo.

The main battery set up photo shows the following wiring: 6v batteries in series; main + terminal has 4 wires attached to it. A 4 AWG wire to main distribution box, 10 AWG wire from Zamp plug, +B1 and +B2 wires from victron shunt; main - terminal has 3 wired attached to it. A 4 AWG wire (black) to main distribution box, 10 AWG wire (white) to "load and charger" terminal on shunt, and 10 AWG wire (white) from Zamp plug. Nothing coming off of the "battery only" terminal on the shunt.

Image: https://us.v-cdn.net/5021717/uploads/editor/87/gb4g6whdsj0h.jpg

Image: https://us.v-cdn.net/5021717/uploads/editor/re/pul3nnufyflh.jpg

Does this explain some of my issues? I believe there should only be one wire attached to the main - terminal of the battery, connecting that terminal with the "battery only" shunt terminal. All other - cables should be on the "load and charger" terminal on the shunt. And the "load and charger" shunt should also be connected to the main distribution box.
From the responses I've gotten in this discussion and my online research I'm thinking it should be wired as follows: switch the 10 AWG wire (white) that comes from the main - battery terminal to the "battery only" terminal on the shunt, switch the 4 AWG wire (black) from the main - terminal and connect it to the "load charger" terminal (thus connecting the shunt to the main distribution box), switch the - 10 AWG (white) Zamp wire from the main - terminal and connect it to the "load charger" terminal on the shunt, keep the + 10 AWG Zamp wire on the main + terminal along with the +B1 wire, remove the +B2 wire completely.

I hope I've typed this up to make some sense.

Cbusguy · April 2020

Holy smokes, they never hooked it up to the battery in a complete manner.

remove the ground connection from the battery, including the two white wires, and connect it to the load side of the shunt, go to the autoparts store and get you a 4 foot or so battery cable, .....and with the newly acquired battery wire go from the "battery Only" side of the shunt to the ground of the battery. You can actually do away with the one white wire from the shunt to the battery ground.

There is really no point in hooking b1 and b2 to the same point, the red shunt wires, as I mentioned earlier they are meant to monitor two seperate batterys.

Denny16 · April 2020

Yes on shifting existing battery net connections to thenload side of the shunt, and adding a wire from battery negative to shunt. You can back pull the battery negative connections out of the battery box and put them through the larger square hole to route them to the shunt. You could add a 40-amp negative buss bar to collect the smaller ground connections and replacemwith a single 8-gauge wire, reducing the number of connectors to the shunt. Then use the battery cable hole (the negative wires were in) to route the new Negative battery cable to the shunt. As Cbusguy stated, remove the extra white wire that the installer used and plug the extra hole he made in your battery box to restore cabin vapor seal (optional, but I would).

As previously stated remove the second B2 wire, or if you want mid point monitoring, then connect the B2 wire to the negative terminal on the other battery positive (when the two batteries are connected together red/black) terminal. The battery temp accessory cable is a different cable See my post below.

I would also send these photos to NuCamp Customer Service, letting them know this was not installed correctly, per Victron guidelines/instructions. Some one dropped the ball here.
cheers

Cbusguy · April 2020

@Denny16 you are mistaken

Image: https://us.v-cdn.net/5021717/uploads/editor/ov/ut6ngtfthnme.jpg

Edit Until your not

Image: https://community.victronenergy.com/storage/attachments/2595-screen-shot-2019-04-18-at-25713-pm.png

Looks like you could purchase a remote temp sensor that can be plugged into the b2 port. Looks like it was offered as an option. It doesnt look like Berrgers has the optional temp sensor

bergger · April 2020

Thanks for confirming what I thought. I did just email this info to NuCamp tech support. Maybe I'll send it to warranty as well. Denny16, the B1 and B2 are actually two separate cables in my install, each with an inline fuse. I don't think it is measuring battery temp, that cable looked different from what I saw in my research. I think it is as Cbusguy said, to monitor a 2nd battery or to the midpoint of a single battery bank. But I don't know where I'd connect it for a midpoint measure. Not even sure I understand what that is anyway!

So you guys recommend I get a 4 AWG (or standard battery cable) cable to connect the main negative battery terminal to the "battery only" stud on the shunt, and not use the 10 AWG cable that NuCamp used to connect it incorrectly? Are the connectors on the battery cables standard size?

Also, I understand the negative cable from the zamp needs to go to the load side of the shunt, but was I correct in keeping the positive zamp cable attached to the positive battery terminal?

bergger · April 2020

Thanks guys. So I can take the B2 wire and connect it to the negative terminal on the main positive side of the two batteries to monitor midpoint. In my photo above that would be the negative terminal of the battery on the left? I think I'm off to get a longer heavier guage battery cable to fix this issue. Hopefully I'll get proper readings after this is done.

Denny16 · April 2020

Correct, all the load negative wires, including the solar controller /zamp go to the shunt. Positive goes to battery side.

The second red wire (B2) can be used to monitor mid-point voltage, see the diagram I,added,in my previous post above.

I forgot the temp accessory wire kit has a red (B1) and a black (B2) temp sensor wire in the set, (wires to positive battery post with yellow tag, just checked myTaB 400 setup shownbelow. (Thanks Cabusguy for the correction)

This is my setup, working with how my battery was changed by a previous owner, I cleaned up some of the cable runs, added the negative buss (at bottom of photo) and installedmthe Victron shunt Battery Monitor. You can see the battery negative jumper to the shunt. The ground buss is connected to the load side of the shunt, along with the rest of the wires formally on the battery post. The two white wires (left and right) are the Zamp and Victron solar charger connections, (left zamp/right MPPT).

I added the wood divider to temporarily block off the battery and all the connections from the rest of the under bed storage area. The battery continues up,along the right side to the back of the compartment.

I left the slack on the main black cable in the middle as I plan to redo this like your battery box/setup is, after my floor is replaced. (Do not want to add any stuff in the way of getting that job done.)
cheers

pthomas745 · April 2020

So...was this set up this way at the dealer or at the factory? There have been several completely wrong solar installations in the last year or so. As these things get more complex, it seems these sorts of issues will continue, and the lack of quality assurance is going to be a continuing problem. Hope someone doesn't have their trailer burn because of this sort of stuff.

bergger · April 2020

Ok so I picked up a battery cable. Tomorrow I'll go back to the trailer and re-wire the bmv shunt. So I'll turn off the battery switch, and to be safe cover the solar panels with cardboard and a heavy shipping blanket prior to disconnecting the battery and everything else. Does it matter the order I connect everything? I figured to connect everything but attach the positive battery cable to the the battery last.

And on a side note I just realized when I opened up the area under the bed I did not see the solar controller anywhere. No clue where they put that in the 2021? I'll have to search for that next.

Verna · April 2020

Didn’t someone else say the solar controller was near the Alde controls as you come in the door? Or was that the Victron? So many things to remember about so many different models!

Denny16 · April 2020

Correction, turn off battery disconnect switch first disconnect the battery ground connection first, an reconnect last. Then disconnect the Red positive battery terminal to insure power is disconnected from the entire system. The MPPT controller in under the bunk driver’s side with with Alde, against the front of the box, on 2018-2020 TaB 400s, that is where mine is at. But it could also be under the closet/refrigerator compartment, remove the bottom drawer to see if it is there, or just follow the MPPT ground wire and see where it leads to... a
After all the connections are made, connect the Positive Red battery terminal, followed by the ground/Black negative batter6 terminal. It may spark, as some TaB circuits are hot even with the battery switch off. Next turn on the battery disconnect switch.

Here is where it is on the 2020 TaB 400, Blue box in upper right side

cheers

bergger · April 2020

Thanks guys. I'll look where the Alde is to see if it's there. I hope so. We have a 2021 with the 3 way fridge. The only other place I could see it hidden is behind the drawer that is under the fridge.

bergger · April 2020

pthomas745 said:

So...was this set up this way at the dealer or at the factory? There have been several completely wrong solar installations in the last year or so. As these things get more complex, it seems these sorts of issues will continue, and the lack of quality assurance is going to be a continuing problem. Hope someone doesn't have their trailer burn because of this sort of stuff.

It was installed at the factory by NuCamp. I'm a bit disappointed with the install we paid for.

Denny16 · April 2020

Verna said:

Didn’t someone else say the solar controller was near the Alde controls as you come in the door? Or was that the Victron? So many things to remember about so many different models!

Verna, that was the Victron Battery Monitor next to the door. The MMPT solar controller is normally under the rear bunk, driver’s side on the 400. That is the first place to look.
cheers

BrianZ · April 2020

Denny16 said:

Correct, disconnect the red battery connection first, an reconnect last.

Are you sure?
I've often seen the mnemonic statement that the red battery cable is positive like the marines, who are always the first ones in and the last ones out.

bergger · April 2020

It's amazing how well things work when they are done correctly! I re-wired the shunt today and both the BMV-712 monitor and the solar controller app seem to be reporting as they should be. At this point it appears all is working well! Thanks all for the advice! I'm still going to follow up wit NuCamp to make them aware of the issue.

bergger · April 2020

Denny16 said:

Verna said:

Didn’t someone else say the solar controller was near the Alde controls as you come in the door? Or was that the Victron? So many things to remember about so many different models!

Verna, that was the Victron Battery Monitor next to the door. The MMPT solar controller is normally under the rear bunk, driver’s side on the 400. That is the first place to look.
cheers

So I did locate the solar controller. On the 2021 400 with the larger 3 way fridge it is mounted below the fridge. Just pull out the drawer that is below the fridge and you'll see it mounted on the wall. Actually very easy to get to.

More questions than answers.

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