voltage

I have installed a Victron 65A LVD in my car to shut down power to a caravan fridge when the car is not running. There is a residual voltage of 2 to 2.8 v when the LVD is either shut down or if the remote circuit is open. Any suggestions?

I have an isolation transformer, model 7000w/230v/32A. My problem is the output voltage is reading 256v. I'm concerned that this higher voltage will damage my appliances. I'm also surprised that it is this high when the input voltage is 240v. Why is the output higher than the input? Everything is wired as per the instructions with a jumper between J5 and J7. Thanks for any advice.

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Hello, I just bought the SmartSolar 250/60 and I observe that the voltage on app is too different than the multimeter measurement.

As you can see in screenshot (taken at night), the controller reads 25.79V on battery and the multimeter 30.12V (measured on the controller’s screws and on batteries).

There is also a big difference on panel’s voltage, for example in the afternoon was ~110V on app and ~125 on multimeter (don’t have a screenshot right now).

My system runs on 24V (2*12V 200Ah batteries), with 3 PVs in series (Bifacial Luxor 540W). No fuses between batteries and controller.

Is there any malfunction on controller?

Thanks in advance.

Update 25/11

The battery once again gave a low voltage alarm while about 80% SoC, causing the inverter to restart. There is clearly something wrong. My best guess (based on many informed opinions) is a serious BMS firmware bug or design flaw. It could also be severely unbalanced cells, or a faulty cell. BSL is apparently working on improving the firmware (they're aware something is wrong).

I'm working with the installer to have the battery exchanged for something that actually works reliably. I would not recommend buying a BSL stubby for the time being, at least not until they sort the BMS issues out.

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Hi,

Hardware details:

• 1 x MultiPlus-II48/5000/70-50 230V
  • Firmware: v481
• 1x BSL Battery LiFePO48 Battery 8.2kWh (160Ah)
• 1 x SmartSolar MPPT 250/100-Tr VE.Can
• 12 x LONGi 450W mono panels
• Cerbo GX
• ET112 Energy Meter

Setup details:

• Grid connected to AC-IN
  • Grid feed-in is disabled.
• AC-OUT-1 is feeding essential loads (no more than 2000W, average about 300W-700W)
• AC-OUT-2 is feeding geyser (on timer 10:00-15:00) and stove.
• ESS mode: Optimised (with BatteryLife)
• The system is less than a week old and has been running perfectly up until a few hours ago.

Issue description:

The inverter suddenly shut down and started up on its own after a minute or two. The battery was about 99% SOC when this happened.

The following alarms occurred:

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On VRM I can also see there was a "High DC ripple" warning at the same time.

The system ran fine after that for a while after which the same thing occurred again, but this time it coincided with a grid failure (load shedding). The same alarms occurred:

[image]

During both occurrences, the load on the inverter was at most 500W (nothing was switched on additionally when it happened).

Does anyone have an idea what the cause could be? I'd appreciate any input.

VRM images (please let me know if other log data could be useful):

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I did also notice on the MPPT daily history, the minimum voltage for the battery today was 44.72V, which seems very wrong:

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Usually it discharges to about 45% throughout the evening, and then the minimum voltage hasn't fallen below 51V before today:

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Hello,

I'm reading in this community for a while now and get many help/hints to setup my storage system. But now I have a questions and didn't find this kind of topic in this community before.

I have just changed my installation from a Multiplus II 3000 GX to a Multiplus II 5000 GX. It is an grid connected ESS System with 5* Pylontech US3000C. Everything works well so far.

But there is one issue that bothers me a bit. The Multiplus have a voltage difference of 0,30 V between the Multiplus itself and monitored in VRM Portal "VE.Bus DC Voltage And Current" and the real voltage. The BMS from Pylontec and all the other voltages monitored and shown by the GX device shows 0,3 higher voltages. I also messured everything with a multimeter and the higher voltages are correct. If I messure also directly with my multimeter on the DC terminal of the Multiplus directly (without calble and inverter/charger are off) the voltage ist 0,3 Volt higher than monitored by the Multiplus.

As the Multiplus uses this messured voltage to steer everything, the real voltage is everytime higher. For example I need to set charge voltage limit to 50,0 Volt to get 50,3 Volt in reality. Also if I don't limit the charge voltage, the real charge limit will be not 52,4, but 52,7.

It may be that these deviations are normal and are the usual variations of measurements. In this case it is ok. But as I still have the possibility to return the Multiplus and to get a new one, I want to be sure. My former Multiplus II 3000 had a deviation of 0,1V.

What are you experiences and values? Are your messured DC voltage by Multiplus the same like messured from BMS/Multimeter/reality or do you have also these kind of deviations?

Many thanks in advance.

Bye Dirk

Hallo,

Ich habe ein 220wp Photovoltaik Leistung auf unserem Camper und eine 280Ah LiFePo4 Batterie. Beide werden über einen Victron 75/10 MPPT verbunden. Die Batterie wird auch über den Landstrom und Lichtanlage bei der Fahrt geladen. Leider hat mein System immer wieder ein Problem, weil die Solaranlage aus unbekannten Gründen die Batterie einfach nicht mehr lädt und die Spannung immer um die 0.1-0.2.V unter der Batterie Spannung "Tänzelt" egal, wie voll die Batterie ist oder wie viel Sonne gerade scheint. Wenn es dann doch funktioniert ist die Spannung bei 30-40V und max 140wp.

Was mache ich hier falsch oder hat der MPPT eine Fehlfunktion?

Vielen Dank für den Support

Philip

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Hello,

I have installed the following off-grid system, which has been working pretty good for one year.

• 4 300W solar panels
• MULTIPLUS-II GX 48V
• SMARTSOLAR MPPT 150/35 48V
• 8 Acid Lead batteries of 6V each (Deka GC15)

However I'm wondering if the behavior I see when I plug a 1200W water heater during the central hours of the day is expected.

As you can see from following graphs the battery voltage drops when load is active and jumps back to an higher value afterwards.

Reading other posts on this subject I've got this is expected indeed, but my question is: do I have to worry about this voltage drop? In other words: should I power on the AC generator if the battery voltage goes down to 46V like in the picture below?

Thanks a lot,

Matteo

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Hi - I have a Multiplus II 12/3000/120-50 2x120V connected to five 12V AGM batteries connected in parallel on my boat. Under normal use the system runs fine. When I try to power the Davit the momentary surge of current to power the motor causes an instantaneous transient voltage drop at the batteries which causes the low voltage shutdown to trigger. The steady state load of the davit is well within the voltage, current and power limits of the Multi. I would rather not lower the low voltage threshold since this could damage the batteries under a normal discharge scenario. Is there any way to set a delay of a few seconds for the low voltage threshold to kick in?

Thank you,

Ralph

I have a BMV-712 connect to 2xVictron Super Cycle batteries, today my monitor started reporting an incorrect battery voltage of 0.02 or 0.03V. This is on both the device itself and the android app (via bluetooth), nothing has changed in my system except for taking a firmware update on the app.

I've checked the voltage with a meter and its reading 13.08 from the shunt to my fuse where the power supply for the BMV is located. I also unscrewed the inline fuse and looks to be intact, just to be sure i checked the voltage from the end of the fuse to the shunt and again was 13.08V so seems to definitely be a software / device issue? I've done a number of factory resets without any joy always just displays the .02V after the reset.

Kind of out of ideas here and would welcome suggestions.

https://photos.app.goo.gl/S9rs1kK25tYuyg4u6

https://photos.app.goo.gl/ZKKrMFAFbc4heScA6

Thanks,
Ian

We have noticed that our voltage drops under 10 so the low voltage alarm goes off. This never happened 2 months ago, but now it is happening more and more. When this problem first occurred, it happened when the battery level was around 20%, but it is coming earlier and earlier. The two last times the low voltage alarm starts when the battery is at 31% , and the voltage seems to be low.

But why does this happen? and why is it coming earlier and earlier?

Wow... I've read a LOT of great info on this site. But there are a lot of numbers and my pea-sized brain still has a couple of questions. Here's what I know: (Please correct anything I've misunderstood!)

* Panels in SERIES Voltages add, and current remains the same, while for panels in PARALLEL their Amps add together and voltages remain the same.

* Battery charging begins once the panel Voltage is more than 5V above the voltage of the battery.

* SmartSolar controllers can handle more amps from the panel(s) than indicated by their model numbers - they just don't push more than that charge into the battery above the limit (eg my SmartSolar 75/15 will limit Amps into the battery to 15A

* Voltage indicated by the model number (eg 75V for my SmartSolar75/15) is a hard limit that will damage the controller if exceeded by the total open circuit voltage stated on the panel(s).

I already have a SmartSolar 75/15 and one 12V 150W panel with these specs:

VOC 22.3V and Vmp 17.9V with max current 8.73A

I currently have a 21V 150Ah AGM battery but plan on replacing it with a 200Ah LiFePO4

I have a second panel the same that is not connected, and the possibility of a separate 310W panel also. Here are the questions:

Assuming I don't want to buy another Charge Controller - 1. If I connect the second 150W panel in Series will I start charging earlier in the day or if its cloudy or partially shaded because the voltages are added and therefore higher earlier in the day than if they were in Parallel?

2. In series voltages add. So 2 panels at Voc 22.3 x 2 = 44.6V This is under the 75Vlimit... any problem with this aspect?

3. In Series the current is the same - since the panels put out 8.73A my 15 A controller wont be close to the max it can push to the battery. Is this a waste of the potential of the panels?

3b. Would It be smarter to put the same 2 panels in parallel, accept that they wont start charging as early in the day or as often in partial shade or cloud but get more amps (which might on rare occasions when everything is perfect exceed 15A since 2 x 8.73A = 17.46A, and therefor be limited to 15 A by the controller)?

4. If i were to replace the 150W panel with a singe 310W 12V ( Voc 40.5V, Imp 9.4A) panel would I get similar results to the total 300W of a 2-panel in parallel setup?

I know there is fair bit here. I hope your answers can not only educate me but also help clarify for future readers who, like me, spent a long time trying to understand this stuff by amalgamating knowledge from previous posts...

Answering these questions should help other Victron users who notice voltage variances on their Victron equipment gauge whether there could be an issue, or whether what they're seeing is considered normal.

1) What is the Volatge metering accuracy of both the internal MPPT and Smart Battery Sense Voltage meters?

2) What is the voltage meter model/part number and manufacturer?

3) How can one be sure they're accurate if they aren't calibrated/checked every year like digital multimerers need to be, especially after 1 year?

4) Testing of equipment is a waste of time if you're not using a guaranteed in spec digital multimeter, Correct?

5) What is the minimum accuracy of a digital multimeter for a reading to be considered "correct" and/or accurate?

Disclaimer:

It seems questions often arise on this forum about the Voltage accuracy of Victron units and variances between voltages measured vs what's displayed on the app.

SINCE there is zero information about the accuracy of the Voltage meters in Victron products, it makes sense that some questions be answered on this community page, which is there to help Victron users!

Elvis, Kevgermany - You didn't like my replies to you and those who commented on my previous question, before you got offended and blocked my account - Maybe go back and read the "so called assistance" that was provided and understand I'm not some completely useless person "like you all suggested" and as a result I gave blunt responses in return showing my appreciation for the RUDE/little assistance and belittlement I received for you.

I fielt my replies were warranted, considering the attitude and belittlement I got from a number of you. All because I don't have access to a "very expensive" FLUKE DMM!

• My questions of how to confirm accuracy of a DMM, fell on deaf ears.

• My questions of the products number/model number of the voltage meters in Victron products, so I could answer the above question, fell on deaf ears.

• My question about how you can all guarantee the accuracy of Victron voltage meters when you all told me that unless a DMM is calibrated every year its not guarantee accurate, so I clearly asked how and why the Victron units can/are still considered accurate when they aren't calibrated every year? This fell on deaf ears.

• How can Victron products be guaranteed to have accurate Voltage if they're not regularly calibrated?

• Exactly what accuracy percentage does a Digital Multimeter need to have to be considered accurate enought to perform testing?

^^^These are SIMPLE QUESTIONS that will help MANY future Victron users and save them from having to create posts/questions when it's already been answered (the whole point of this community according to community guidelines)...

Let's watch you delete my account again for trying a second time to ask BASIC questions all because you assume I'll abuse you - The difference is that if you actually provide clear answers and don't provide VAGUE information, or try to waste my time asking for irrelevant information and/or imply I'm useless, then my replies will be respectful.

If you waste my time again, be rude or vague you will get blunt/rude replies in return - Not sure why you're surprised by this.

* I've been told I'm blunt due to my Autism, but that won't change the sour people who have been offended at my responses to them after they wasted my time, or implied I am useless (which in itself) is very insulting to me!

^^^ You offended me and/or wasted my time first before I gave it in return...

Hello,

the multi is always reading voltage about 100mV to low also in no load conditions.

After disconnecting the multi for a few minutes the voltage reading is ok, but it’s getting worse after some time.

BMV 712 and BMS and multimeter is measuring the same voltage, only the multi is reads wrong voltage.

The absorption and float voltage is getting also about 100mV higher as programmed voltage.