Victron mystery?

[GallenH]

I accidentally left some things on in the RV and ran down my 100AH LifeLine AGM cabin battery. My wife noticed the idiot light monitor said empty. So I checked my Victron battery monitor and the attached images show what I saw.
Actually LifeLine says total discharge is at 10.5v. But I must have something set incorrectly on the Victron app. I do have it set for 100AH battery capacity.

So why does the Victron say 100%? Shouldn't it read like 10%? Why does it read that 0.0Ah have been consumed? Clearly I've missed something in the setup. Any help appreciated. Glenn

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[@Michael]

What's are the settings for 'Charged Voltage', 'Tail Current', and 'Charge Detection Time' on the settings screen?

7.1.2. Charged voltage

The battery voltage must be above this voltage level to consider the battery as fully charged. As soon as the battery monitor detects that the voltage of the battery has reached the “charged voltage” and the current has dropped below the “tail current” for a certain amount of time, the battery monitor will set the state of charge to 100%

7.1.4. Tail current

The battery is considered as “fully charged” once the charge current has dropped to less than the set “Tail current” parameter. The “Tail current” parameter is expressed as a percentage of the battery capacity.

Remark: Some battery chargers stop charging when the current drops below a set threshold. In these cases, the tail current must be set higher than this threshold.

As soon as the battery monitor detects that the voltage of the battery has reached the set “Charged voltage” parameter and the current has dropped below the “Tail current” for a certain amount of time, the battery monitor will set the state of charge to 100%.

7.1.5. Charged detection time

This is the time the “Charged voltage” and “Tail current” must be met in order to consider the battery fully charged

[GallenH]

Thx for rapid reply. Charged voltage = 14.2. Tail current = 0.5%. Charge Detection time = 3 min. So the battery was depleted when I was obviously not on shore power. I connected to shore this morning and now it shows:
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That display appears more reasonable. Question still remains why I was getting a 100% reading when not on shore and depleted. Does the charge detection time mean I would have to have the app open for 3 min to get a current reading?

[tgregg]

is the shunt the only thing connected to the negative post of the battery?

[GallenH]

No but the only other thing is a line that goes to a solar outlet that I connect my portable solar panel to and that’s not currently connected. So effectively there is currently nothing connected except the shunt

[@Michael]

Originally Posted by GallenH

Does the charge detection time mean I would have to have the app open for 3 min to get a current reading?

Shouldn't matter.

A mystery.

[Uncle_Rico]

Maybe shunt is installed backwards? What was happening when you took the screen shots? I'm not that familiar with the Victron app but I thought a positive current (0.37A shown above) means it thinks you're charging.

[booster]

Originally Posted by Uncle_Rico

Maybe shunt is installed backwards? What was happening when you took the screen shots? I'm not that familiar with the Victron app but I thought a positive current (0.37A shown above) means it thinks you're charging.

I don't think the shunt itself is one way or the other, but if the small screw sensing wires to the meter are backwards then the plus and minus currents will be backwards also.

[Winston]

Originally Posted by booster

I don't think the shunt itself is one way or the other, but if the small screw sensing wires to the meter are backwards then the plus and minus currents will be backwards also.

Booster, the Victron shunt does have a 'built-in' RJ-11 jack/circuit board(?) that connects the shunt to the Victron "meter head" (through an RJ-11 'telephone' cable). As such, it is polarity sensitive. To install the Victron (712), all one has to do (other than connect the shunt in the proper direction) is plug the RJ-11 cable into the shunt (and Victron meter) and run a small red power lead (from the shunt circuit board) back to the positive terminal of the battery.

[booster]

Originally Posted by Winston

Booster, the Victron shunt does have a 'built-in' RJ-11 jack/circuit board(?) that connects the shunt to the Victron "meter head" (through an RJ-11 'telephone' cable). As such, it is polarity sensitive. To install the Victron (712), all one has to do (other than connect the shunt in the proper direction) is plug the RJ-11 cable into the shunt (and Victron meter) and run a small red power lead (from the shunt circuit board) back to the positive terminal of the battery.

So Victron is using a device specific shunt? Never seen a meter that way myself always generic shunt with meter 4 wires on the two small screws on each end of the shunt. The must be a quite expensive shunt compared to the generic ones. Do they also have them in different amp range sizes like others do?

[GeorgeRa]

Do you know what 0.37A draw/charge relates to? Is you current draw displayed on Victron represents actual loads, even approximately? Turn on some loads and monitor display on Victron.

[Winston]

Originally Posted by booster

So Victron is using a device specific shunt? Never seen a meter that way myself always generic shunt with meter 4 wires on the two small screws on each end of the shunt. The must be a quite expensive shunt compared to the generic ones. Do they also have them in different amp range sizes like others do?

We think, otherwise, it's a normal 50mV/500amp shunt, but they've added on a few connectors/circuitry to make it a simple install. As to expense, well, Victron is not known for their 'economy of price'. We're not overly familiar with the breadth of the Victron line . . . but we think the Victron 712 has a 'one size, fits all' shunt. There's a lot of programming one can do . . . but, again, we believe it's all based on the 'same' shunt. We bought the Victron 712 as a 'back-up' when our primary battery monitor/BMS failed us . . . so now we have two series shunts in our negative lead. And it has been interesting to compare the two systems - - happily they (mostly) agree.

[GallenH]

Originally Posted by GeorgeRa

Do you know what 0.37A draw/charge relates to? Is you current draw displayed on Victron represents actual loads, even approximately? Turn on some loads and monitor display on Victron.

Nope. As you can see, it's gone from the second reading on shore power. Which I also don't understand since the LP and CO detectors should have some draw. I have watched the Victron app in the past when I turned on ceiling fan or my fridge fans and they showed draw. Also get about a 10-11A draw when I put the fridge on 12v (which makes sense since my Dometic has a 125W 12v element).

Bottom line is if I check battery and it reads 100% when the battery is much less, what's the point in having it.

I'll run some more tests.

[booster]

Originally Posted by GallenH

Nope. As you can see, it's gone from the second reading on shore power. Which I also don't understand since the LP and CO detectors should have some draw. I have watched the Victron app in the past when I turned on ceiling fan or my fridge fans and they showed draw. Also get about a 10-11A draw when I put the fridge on 12v (which makes sense since my Dometic has a 125W 12v element).

Bottom line is if I check battery and it reads 100% when the battery is much less, what's the point in having it.

I'll run some more tests.

Battery monitors can read way off for a few reasons, but far and away the most common one is that for being off of actual state of charge is that the "full" charge point from your charging sources is not getting the battery to the point where the monitor does a 100% reading calibration reset.


You should be able to what the monitor charging the battery and the SOC % increasing as it does. At some point the charger will shift to float voltage and the amp in will reverse, even with no loads on, as the surface charge dissipates. Just before the the charger goes to float, the monitor should reset whatever SOC percent it is showing to 100% to indicate the charger has reached a full charge. This is the calibration procedure that has to happen on most every recharge to be able to maintain discharge SOC percent accuracy.

It is very possible, and especially likely with lead acid, that the charger does not get them full but for accurate usable power you need to setup the monitor to compensate for that.
The process and settings procedures to do that are in many place on this forum.
If you don't see the above happening when you recharge, you will never have enough accuracy in the monitor to be able to have it be useful.

[tgregg]

Originally Posted by GallenH

Attachment 13639

The history display raises a lot of questions. Deepest discharge 37ah, last discharge 0ah average discharge 0ah but total discharge 1170ah?

Total energy consumed 15kwh equals the 1170ah but total charge energy of 59 kwh is about 4500ah?

24 synchronizations means 24 times the charge voltage, tail current and detection time met the parameters for fully charged.

Have you ever manually synchronized the battery monitor?

Is the battery monitor always powered on? Or can it be turned off?

Do you have a wiring diagram?

How long has the monitor been installed?

[booster]

Originally Posted by tgregg

The history display raises a lot of questions. Deepest discharge 37ah, last discharge 0ah average discharge 0ah but total discharge 1170ah?

Total energy consumed 15kwh equals the 1170ah but total charge energy of 59 kwh is about 4500ah?

24 synchronizations means 24 times the charge voltage, tail current and detection time met the parameters for fully charged.

Have you ever manually synchronized the battery monitor?

Is the battery monitor always powered on? Or can it be turned off?

Do you have a wiring diagram?

How long has the monitor been installed?

Some of the oddness can probably be explained and semi normal, I think, in a system that had solar putting charge on full battery every day or on float a lot if the settings were still on the very conservative Victron defaults that can generate a reset and float voltage in some cases.


But with settings of 14.2v and .5amps synchronization trigger there it is highly unlikely any charge source, that is not tail amp controlled would charge to that level except maybe solar that did a full charge every day on a full battery (bad thing) or driving a long distance at over 14.v from the alternator which is more likely. The much higher total charged than used would often indicate solar doing a charge on a full battery everyday and/or the unit being being in float storage fro a long time as that is all small amounts of continuous power input that is on a full battery so cannot ever be used.


There has to be something that is not right in the system or monitor and as said a complete wiring diagram would certainly help.


Hopefully, it will be something like a reversed wire or loads that are on the wrong side of the shunt or other easy to spot things. Of course it could just be a bad monitor also or some setting got messed up. Doing a full factory reset of the monitor to take it all the way back to default might be a good idea at this point and then go in and just set battery type and size to see what happens then.

[@Michael]

Originally Posted by GallenH

...get about a 10-11A draw when I put the fridge on 12v (which makes sense since my Dometic has a 125W 12v element).

Then it's not hooked up backwards.

Is it possible that you have another path to ground for some of the loads?

I had this on my campervan. Path to ground for a fraction of the current was via the generator frame, so it was impossible to get an accurate reading from any shunt on the ground side. I ended up using a shunt and monitor that was rated to work on the 12V side.

[avanti]

Originally Posted by @Michael

I had this on my campervan. Path to ground for a fraction of the current was via the generator frame, so it was impossible to get an accurate reading from any shunt on the ground side. I ended up using a shunt and monitor that was rated to work on the 12V side.

I don't think I understand.
If there is no bond between the negative battery terminal and the chassis, why should multiple paths to the chassis matter?
Am I missing something?

[booster]

Originally Posted by avanti

I don't think I understand.
If there is no bond between the negative battery terminal and the chassis, why should multiple paths to the chassis matter?
Am I missing something?

All us have multiple paths, if we didn't we would a huge rats nest of more wiring. As long as all the grounds go to the chassis or directly to non battery side of the negative and the shunt to chassis wire is on that same end you are fine as long as nothing is on the battery end of the shunt except the battery.

[@Michael]

Originally Posted by avanti

I don't think I understand.
If there is no bond between the negative battery terminal and the chassis, why should multiple paths to the chassis matter?
Am I missing something?

From the factory, my generator starter motor is connected directly to the coach batteries and is also grounded to the chassis via the generator frame. When the coach<->chassis battery combiner relay is closed, return current between the two banks could take the path from chassis ground through generator chassis and back to the coach battery ground. I could have captured that current by moving the generator starter motor ground from the coach batteries to the frame, but the existing ground from coach battery to the inside of the coach where I room for a shunt is only 6ga, not ideal for the generator starter motor.

It was simpler to use a monitor that works on the +12V side. I still don't capture the current used to start the generator though.