Victron Battery Monitor Does Not Like the Humidity

jkjenn · September 2018

One of the cons to mounting the Victron shunt outdoors is that it does not like the humidity. It has been dead for the last 3-4 days, or so, following our recent deluge, from TS Gordon. Although it was completely dry, the humidity still managed to impact the monitor. I had actually planned on installing a new one but, thankfully, that will go back to Amazon, when it arrives.

I have been seriously considering moving my batteries, solar controller, and shunt to the passenger side this winter. It looks like I will be doing that...or, at least letting Austin take care of it.

Another round of rain is expected from Florence, early next week and I hope the monitor is working when I leave for my trip at the end of the week. I am moving my trailer off of its stone patio to the driveway tonight, after work so that I do not worry about getting stuck when it is time to go. Our ground is really saturated.

rajamar · September 2018

Good luck, stay dry and be safe!

Sharon_is_SAM · September 2018

Sorry, Jenn. At least it will dry out when you get out west!

jkjenn · September 2018

Sharon_is_SAM said:

Sorry, Jenn. At least it will dry out when you get out west!

So true!!!

OpenSky · September 2018

Sorry to hear this.

I am curious what the failure symptom is, and how your shunt is protected from the environment. I just installed mine in a non-hermetically-sealed box (intentionally). I'd expect humidity to degrade performance, not cause a failure, and the degradation would be proportional to the salinity of contamination (dust) deposited on the shunt. Are you in a coastal environment? "Florence" of course means you are near the coast, but is it close enough that you deal with saline spray?

I'd infer from your post that the power to the Victron dropped sufficiently to kill the monitor. That power comes from the same RJ-12 connector, so I could see that being a fatal design flaw.

(In the meantime, my mind is actively working on a design for a bolt-in shunt which does not require environmental protection. Along with at least 50 other really-cool projects, most of which have nothing to do with my T@B)

Sharon_is_SAM · September 2018

Our Victron shunt is inside the wall on the outside of the shower accessible via a hatch at the base of the cabinet. It was installed on build. Not sure how easy it would be to access that area now, but I think you can just run the negative battery lead in and out through the front of the TaB and mount the shunt inside the cabinet.

jkjenn · September 2018

Symptomns are blank screen and no Bluetooth. Also, when working giving lowball numbers compared to testing with a multimeter.

I do not live anywhere near the coast, but we had rain from the remnants of Gordon and Florence. Gordon was actually worse. However, it has been a very damp summer, here in W PA.

It was dead, again and then kicked back on.

I keep the shunt in the diamon plate tub, inside of a rubbermaid box, which holes cut for cable pass throughs.

It looks like I might be installing a new one in the off season, but I will likely move it inside, along with the AGM batteries and solar controller.

OpenSky · September 2018

Blank display suggests the head is not getting power. I'm assuming electrical loads (lights, etc) operate properly, so the shunt provides a proper battery ground to the trailer. This suggests a bad power connection. Things you might do:

- inspect/tighten the red wire ring terminal on the + terminal of the battery (to the shunt)

- inspect/wiggle the crimp on the red ring terminal. Corrosion products inside could expand with moisture and reduce conductivity.

- check the fuse/fuse holder in the red wire.

- remove/reseat the pin from the red power wire at the shunt.

- remove/inspect/reseat the RJ12 connector at the shunt

I'm skeptical anything on the shunt (other than the two connectors carrying power) on the shunt above could cause such a problem.

Do all wires connected to the shunt hang down such that condensation would drain away from connectors?

dhauf · September 2018

I’ve noticed the rj12 connectors can get corroded and not work correctly once moisture gets on them, as @OpenSky had mentioned in his post that would definitely be one area I would check also. Perhaps a new rj12 cable can get it working correctly again.

Sharon_is_SAM · September 2018

https://tab-rv.vanillacommunity.com/discussion/7396/victron-bmv-700-battery-monitor-display-troubleshooting

@jkjenn, It just dawned on me that I addressed this problem. That little fuse in the small, red + lead between the battery and the shunt collected water. John just cleaned the fuse and dried out the fuse holder, then sealed it up. With all the rain you have had, I’ll bet it is due to that!

jkjenn · September 2018

Awesome! Will try it. It is working great, right now.

ChanW · February 2019

To resurrect an old thread (once again forgive me!), jenn, did you ever resolve this problem with this device?

Would dielectric grease on/in the various connections might have prevented the problem?

I'm looking into the reliability of the Victron battery monitor, and wonder what you think of it at this point. It seems like a nice device, small and simple with a clean interface. Also, do you think the Bluetooth capability is useful enough to justify the higher cost?

jkjenn · February 2019

ChanW said:

To resurrect an old thread (once again forgive me!), jenn, did you ever resolve this problem with this device?

Would dielectric grease on/in the various connections might have prevented the problem?

I'm looking into the reliability of the Victron battery monitor, and wonder what you think of it at this point. It seems like a nice device, small and simple with a clean interface. Also, do you think the Bluetooth capability is useful enough to justify the higher cost?

I am sure the problem was thencinstand humidity we had last year. We actually exceeded Seattle in cloudcover last year and set a new annual rainfall record. The NWS shared a graphic at the end of the year that showed a significant deviation from average dew point, last year. I really think it was an anomoly.

On my annual, "well visit" to Sugarcreek, installing the new monitor, along with the solar is on my to do list for Austin. I think I will ask that it be installed inside, too. They are clear about the shunt not being meant for outside and I pushed it. There is a little circuit board on the shunt and I am sure that was part of the issue.

ChanW · February 2019

Hmm. Not outside huh? That's too bad. ie The inside of an RV, when not in use (pretty high percentage of the time in most cases), is not much different from outdoors in relative humidity.

If (when?!) I convince myself that the Battery Monitor is a necessary mod for us, I hope they've addressed this requirement. I'd hope dielectric grease would be enough. I wouldn't expect the circuit board itself to be sensitive to dampness in the air, other than the various connections.

BrianZ · February 2019

@ChanW,

I coated my shunt's circuit board with a silicone "conformal coating" designed to protect circuit boards from water exposure and installed it in a junction box.
If you select the "Battery Monitor Installation" link listed at the end of my topic here..
http://tabforum.nucamprv.com/#/discussion/7926/boondocking-our-first-experience-documented
..you'll see near the beginning where I listed the source for the coating liquid & how I used it.

Also installed the shunt in a junction box for added protection. It's only been about 5 months, but we've had a lot of wet weather and haven't had any problems so far. I'm hoping this will be good enough.

Another idea I had before I learned about the silicone coating was to just to encase the whole little circuit board & connectors with hot melt glue or some silicone caulk, which I figure could be cut off if needed (test continuity/resistance first with a meter for non-conductivity of the dried caulk/glue). I may still do this after the warranty period is over.

jkjenn · February 2019

ChanW said:

Hmm. Not outside huh? That's too bad. ie The inside of an RV, when not in use (pretty high percentage of the time in most cases), is not much different from outdoors in relative humidity.

If (when?!) I convince myself that the Battery Monitor is a necessary mod for us, I hope they've addressed this requirement. I'd hope dielectric grease would be enough. I wouldn't expect the circuit board itself to be sensitive to dampness in the air, other than the various connections.

I don't disagree. Like I said, last year was a significant departure from the norm and probably would not have been an issue, otherwise. I even have a little, what I believe to be mold on the interior, rear plywood floor behind the bench, which I will have replaced. I probably should have got some of that damp RID stuff and will likely from now on have some on hand. Have I ever mentioned how much I despise humidity?

I also usually leave the vent open so that the trailer can breathe, since I have a cover. I probably will not do that, again, either.

BrianZ · February 2019

@ChanW, here's a related discussion & where I learned of the conformal silicone coating from @dhauf ..
http://tabforum.nucamprv.com/#/discussion/7779/no-12v/p1

N7SHG_Ham · February 2019

Victron has a lot of presence in the boating community, I am very surprised that gear from them wouldn't tolerate humidity?

jkjenn · February 2019

N7SHG_Ham said:

Victron has a lot of presence in the boating community, I am very surprised that gear from them wouldn't tolerate humidity?

They are pretty clear about the shunt not being exposed to the elements.

ChanW · March 2019

(I see this reply was never posted!)

Thanks @BrianZ. That was going to be my next question!

BrianZ said:

@ChanW, here's a related discussion & where I learned of the conformal silicone coating from @dhauf ..
http://tabforum.nucamprv.com/#/discussion/7779/no-12v/p1

ChanW · March 2019

Is there any reason that the battery temp sensor wire can't be extended if needed?

ie: Wouldn't installing the shunt inside the Tab, and breaking the negative battery wire nearer the converter, make sense, to address moisture protection?

In which case, the only wire(s) needing to go through the Tab's 'firewall', into the battery tub, would be for the battery temp sensor.

Temp sensor has a smaller wire. Easier?

jkjenn · March 2019

@Sharon_is_SAM how did nuCamp wire your shunt? Is there a negative that goes from battery to shunt and then from shunt to bus bar?

Sharon_is_SAM · March 2019

Yes, that is exactly how they did it.

BrianZ · March 2019

@ChanW, If you extend the battery temp sensor wire, I would suggest using a thicker gauge wire to minimize the voltage drop.
PS: You might also want to first test a longer wire to see if you get the same temperature reading as with the normal length one. If it's a thermocouple type of sensor as I suspect & using a special metal in the sensor line to compare to the other small power line as a reference, then it's possible that both victron power & temp battery lines would need to be extended in a similar manner to get the same reading, but maybe not. You might want to ask Victron too.
PS2:
I've learned it is a bead thermistor sensor & have inquired here on your behalf regarding extending the cable..
https://community.victronenergy.com/topics/Temperature+Sensor.html

BrianZ · March 2019

@ChanW, one suggestion regarding extending the battery temp sensor wire was to get their bluetooth sensor for the charge controller, though some reviews indicate range limitations..
Victron Energy Smart Battery Sense (Bluetooth) https://www.amazon.com/dp/B07BN7WVB9
Not clear to me if this can work with the BMV monitor.

ChanW · March 2019

Thanks @BrianZ.

I'd looked into the 'stand alone' temp sensor that you refer to, that connects directly to the controller. The higher price made me rethink it. But now that I think about it, it's probably worth $20 just to avoid fishing any wires through the Tab's 'firewall'!

I'll look into it some more, and ask Victron about it's function-ability with the BMV.

That would be an easier install all around, simply mounting the shunt near the converter, and only running wires within the Tab.

Edit: oops. I just realized, I can't mount the shunt away from the battery and inside the Tab, because (from what I understand) the solar needs to connect to the negative battery lead on the 'Tab' side of the shunt, as opposed to the battery side of the shunt...

So, a further question. The shunt can handle the potentially high current that the solar charge controller puts out (12A in my case)?

Sharon_is_SAM · March 2019

@Chan, if you mean the negative lead from the charge controller, the factory connected ours at the junction box under the front of the TaB and our shunt is inside.

ChanW · March 2019

@Sharon_is_SAM, in that case, I'm confused.

My understanding of it is that the shunt measures all power going out of, and into, the battery, and that all negative terminal connections need to be after the shunt, including the solar panels (charge controller).

If the charge controller is connected to the negative lead from the battery before the negative lead gets thru the shunt, then the shunt won't see the power from the panels...

Does your negative lead go from the battery negative post into the Tab, then through the shunt, and back out of the Tab to an external negative bus bar, where the SCC controller is connected?

What am I missing?

jkjenn · March 2019

ChanW said:

@Sharon_is_SAM, in that case, I'm confused.

Does your negative lead go from the battery negative post into the Tab, then through the shunt, and back out of the Tab to an external negative bus bar, where the SCC controller is connected?

What am I missing?

Affirmative...see the post from me and Sharon's response, above.

Bus bar is the key ingredient.

ChanW · March 2019

Ok. Got it! Not confused after all. However that's too many wires in and out for me! Trying for simple.

I'm now considering mounting the BMV in the tub. Along with the shunt, of course.

N7SHG_Ham · March 2019

@ChanW the shunt included with the BM 712 can handle 500 AMPS per specs, I would say your 12A is going to be OK. That shunt measures every electron flowing into the negative terminal and every electron flowing out of the negative terminal on the battery. Every 12v load or charge source needs to flow through it, nothing should be hooked to the negative battery terminal but one end of the shunt, all the "stuff" hooks to the other end or a buss bar hooked to the other end.

Victron Battery Monitor Does Not Like the Humidity

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