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Affect temperature the open circuit voltage in agm lead acid Victronenergy?
Hello, I have a victronenergy aGm deep cycle 110ah battery with an age of 8 months of cyclic use. About 300 cycles. Each day at a 75% SOC (25% DOD).

I know that the capacity is reduced in the cold.
But is the open circuit voltage also reduced?
From 1 month the temperature in the evening of the battery has dropped from 26/29 C to 18/21 C.
And with the same SOC and the same discharge current, I notice a drop in open circuit voltage of about 0.06 / 0.08v.
All data comes from the victronenergy smartshunt.
I give some examples:
With -6ah before until a month ago it was 12.98v. Now 12.92 / 12 94v.
With - 12ah before it was 12.88v / 12.90v. Now 12.81v / 12.84v.
With - 19ah before it was 12.76v / 12.78v. It is now 12.69v / 12.71v.
Etc etc.
I've been recording open circuit voltage with NO LOAD every night since I bought it.
ALWAYS 100% charged with mppt controller every day (boost 1 or 2 hours at 14.5v and slight equalization once a month 2.5 hours at 14.6v, float at 13.7v. Temperature compensation - 4mV / C x element. All exactly as per Victronenergy data sheet.

The first month I noticed a slight increase in the open circuit voltage for each discharge. (I have read that there is a slight increase in the capacity for full plate formation at the beginning).
Then in the summer it was stable, and now, for about 1 month, from the end of October, I notice this drop in the open circuit voltage of 0.06 / 0.08v for each discharge.
The only change was the temperature which dropped by 7 / 8C on average every night.
Is this behavior normal?

francesco asked
francesco commented ·

0 Answers

I’m only getting 3-4V readings on Inverter, whether inverting or in standby mode?

Running 300Ah of LiFePO via 100/50 64V 9.6Amp 600W Solar Array in Trailer to 12V Multiplus 2Kw.

bfd1 asked
kevgermany answered ·

1 Answer

Voltage Drop on Controller in Panel Series

Running a 3 panel, 600W array in series, producing 64-66 max open voltage, and around 56V nominal, into a 100/50 SC. Sometimes I’ll get 64+ voltage readings, 200W or so, 4 amps (it’s late November); other times it will drop to 20 or 40 Volts.


bfd1 asked
Alexandra edited ·

1 Answer

Superpack Voltage loss/fluctuation

I have a pair of superpacks in parallel connected to a motor. The circuit had been tested and in use with no issues, other than motor is too fast. ive connected a motor controller to the circuit output without the motor and applied power to make sure the speed controller would turn on and was trying to measure output. I cycled the power to this speed controller vie momentary switch for very brief period, 1-2s, and when trying to go reverse direction was unable to power my relays and voltage was reading 0-5Vmax and fluctuating like crazy. i figured the protection activated as the speed controller must have over amped the batteries but it now will not reset itself. the data sheet indicates this safety is present and should reset itself within 10s. once again the output was only engaged for very brief time and load completely removed from battery so it should have been taken out of any "abuse" states very quick. when i connect to a charge to try to reset, i am able to read full charger voltage and the battery accepts current ~3A as was near 100% at time of incident. Has anyone experienced activating this internal safety and what measure can be done to reset it? or am I out 2 brand new batteries?

sc-kevo asked

0 Answers

MultiPlus-II sudden low battery alarm while battery is full (BSL stubby)

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.



Hardware details:

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:


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:


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):





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


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


anrich asked
anrich edited ·

3 Answers

Autotransformer output not 120v

Hello. Is my brand new 100a autotransformer defective?! It is putting out 120v and 114v on each leg.

Can I fix this? What do I do?

georgev asked
echidna answered ·

4 Answers

Multiplus II shutdown with Generator

Hi there

I built a stand alone system consisting of 1Kwp of solar panels, a Victor mppt charge controller, a Multiplus II and a 16s 48v 176Ah lithium battery pack.

the system has been running for about 4 months and is working great and I'm really happy.

In the last days I tried to connect a Honda ex4000s generator, unfortunately initially the system did not accept it, and I had to change the software settings.

I disabled the UPS function, enabled the dynamic load limiter and enabled the WEAK Ac input.

With all these values set, the multiplus was able to recognize the generator and charge the batteries with a current of 20A.

On the CCGX, however, were not shown the watts entered into the system by the generator and Ac loads, for both loads were shown 0w, while in the detail of the battery was shown + 1000w approx. (This is the first problem)

The real problem is that after a few minutes that the generator is on and the batteries are charging the multiplus turns off and then back on without recognizing the current of the generator and taking the current for the loads from the battery.

I have noticed that the voltage of the batteries during charging varies from 54 to 57V in a few seconds oscillating up and down just before shutting down. It does not do this initially, initially the voltage rises smoothly and slowly. However, it does not report a DC Voltage ripple alarm.

I also noticed that the voltage and frequency of the generator varies suddenly before shutting down. The voltage goes from 215v (strange because the generator output is 230v) to 236v while the frequency goes from 50hz to 52.8hz after which the multiplus II shuts down.

Another thing I noticed is that the status of the charger doesn't reflect the state of charge it should have, even if the batteries are discharged, the "Absorption" function comes on after a few seconds instead of starting in "Bulk".

The change in voltage and frequency could be the change in load, but why is the multiplus shutting down ? With the current settings according to the Victron manual the multiplus should be compatible with any generator, simply having less efficiency.....

All connections have been checked and are all tight, even the cable sections have been checked.

Thanks in advance for your help



marcmu asked
Andrey answered ·

2 Answers

Multiplus II charger voltage inaccurate

I just installed a MP2 in my RV. The charger is set up according to the setting recommended by the battery manufacture: Absorption 14.4V and Float of 13.8. Most of the time the MP shows appropriate DC voltage in this range but only produces around 13.1 to 13.5 V verified by a multi meter. This low voltage allows the battery to discharge even while plugged into shore power. If I change a setting by even .01 V on the MP, it quickly displaces it current produced voltage and then jumps back up the appropriate charge voltage and charges the battery. This however only stays this way for a short time and then the voltage being produced drops back down in the 13.2-13.5 range while the display still shows a voltage in the 13.9-14.2 range. I have updated the firmware, but that did not seem to make a difference. Both picture were taken at the same time. Any suggestions?



pilotchuckles asked
pilotchuckles commented ·

3 Answers

High grid voltage disconnect with Multiplus II in AU, why?

Lets be clear, I understand that power generators should not feed in energy if the grid voltage is already high, hence the regulations around handling high voltages. Hence the locked-in grid parameters.

I have recently has "grid lost" for short periods in the middle of the day when high voltages were sustained. Circuits upstream of the inverter were not affected by a power loss - that made it was clear that the MP2 disconnected itself from the grid. The MP2 went into "Inverting" mode.

The question is "why disconnect from the grid?". Why does the MP2 not simply go into "pass-thru" mode or a "zero-export" mode? To me this seems much more sensible. It achieves the desired outcome of removing the generator from the grid while not drawing down on batteries needlessly.

Is there any way to change this behavior in response to high (10 min moving average) voltages? (yes, ideally, fix the voltage issues but ...)

thank you,


rrroonn asked
ian-stewart commented ·

2 Answers

BMV-712 suddenly displaying a wrong voltage of 0.02V

I had my BMV712 running for some weeks now. This weekend during dischcharge, the main battery low voltage alarm suddenly triggered. The main voltage was displayed as 0.02v.

Link to screenshot: https://photos.app.goo.gl/9BJSLhVN2tJe5Yvk6

this was during normal operation of our camping car. whilst no change was done to anything...
i checked the "real" battery voltage using a DMO and it was 13.x volt.
i quickly inspected all the cabling, but all seemed correct. (and all other values including current from the shunt looked correct..
I then did a reset to factory settings and the voltage was back to normal display (but it started with 100% capacity..) .
It seems to me like a software problem as the only thing i did to resolve it was a factory reset...

Any ideas or suggestions? or is the unit defective?

derrainer asked
kevgermany answered ·

2 Answers

Orion Smart input voltage 12,3 volts due to the app. Multimeter shows 13,8 volt.

After installing the isolatef Orion 30/30 in my Van it worked properly for 2 weeks. Suddenly charging stopped due to low input voltage. In the app the inputvoltage seems ‘stocked’ at 12,3 volt. When i measure the input (at the Orion) after starting the engine it’s about 13,7 volt. I reinstalled the fabricsettings, checked the wiring and the fuse near the battery. What can be the ‘problem’?

dirk-jan asked
Mike Dorsett answered ·

1 Answer

Multiplus 2 Output Voltage


I have 3 Multiplus 2 inverters with 3 phase connection. The problem is that the AC output voltage of one of the inverters has reached a value of 300V and reached 190V on another one ( the output voltage is set to be 230V)

This problem caused great damaged to the clients electrical equipment.

The problem only occurs when Grid power is ON. I tried disconnecting the grid and everything went back to normal.

I tested the AC input voltage and it has a value of 230V so the input power could not be the problem cause.

Tgere is nothing wrong with the inverter connections.

What might be the problem?

hanyhc asked
basil katakuzinos answered ·

3 Answers

Multiplus 5kVa "low Power" state


I have a client with a Easysolar 5kva (multiplus 5kVa). Stand alone, lead acid batteries.

System has been working for several months. AC output is locked at 151V. I have checked & Re Entered settings in VE Config to ensure output is set to 230V.

State on Colour Control is "Low Power".

Batteries are fully charged and in good condition.

See Screenshots below.

Any Idea's?



ngillam asked
kevgermany answered ·

2 Answers

Autotransformer voltage outputs are different

I am having an issue with the Autotransformer output voltages - 114V on L1 and 120V on L2 (with no load)

120V current is supplied by a Quattro 48V / 10000 / 140-100/100 to the 100A Autotransformer. I'm using the AT to provide a split-phase 120/240v supply to the 50A main break panel in my RV

I have wired the AT connections according to the diagram #3 shown on the system schematics page from the Victron website: (https://www.victronenergy.com/upload/documents/AT-3-split-phase-120V-to-120-240V-with-Quattro-120V.pdf)

The Ground Relay in the Quattro is set to ON and is correctly grounding the Neutral to earth.

Here are the voltages I read at the terminals:


The problem I have with this is that the voltage on L1 decreases a lot with load, and when occurs equipment will pull more current to compensate for the lower voltage.

Here is a pic of my RV control panel, showing the disparity in voltage between L1 and L2. Even though there are 2 air conditioners on Line2 it has only dropped 2 volts - Line1 dropped from 114v to 105v. This can't be good.


Questions: 1) - Is this method of wiring correct, and 2) what is causing the voltage discrepancy?


Aug-31: Editing this in an attempt to make the question visible again. I'm thinking of sending this AutoTransformer back to Victron as it is not performing to expectations. I have seen voltages as low as 96 volts on L1, at which point my UPS shuts down my computer, and various other circuits shut down. Not happy...

I'd appreciate a comment from anyone who has had experience with an AutoTransformer.


Pete MacLachlan asked
irwinr answered ·

5 Answers

Bluesolar 75/50 gets to float voltage too early.

Seen some with similar problem but not seeing many answers. Please help. Trying to improve SOC during daylight hours. Have Smartshunt onto 600Ah Lithium. Po4. Come the afternoon, solar producing close to 50Amps. The voltage moves increasingly higher and then goes into Float. Float set at 14.2v. Trying to keep voltage low and Amps high to increase SOC. Is the charger regulating the max. Output by increasing the charge voltage? When I turn the charger off for a few minutes, voltage regulates to below 13.8 and charger goes into Bulk mode with higher charging current obviously. Running VE Bluetooth dongle and Smartshunt networked

wisey asked
klim8skeptic commented ·

5 Answers

Blue smart IP 22 12/15 (3) voltage display

Why do the voltage readings in the application and at the battery terminals differ by 0.1-0.2 v? I use a cable 6mm2, length 1m.

Is it possible to programmatically implement voltage compensation for the cable? I understand that I can compensate manually, but this is not the Victron level

Олександр Королюк asked
Alexandra edited ·

1 Answer

MPPT 75/15 low input voltage

Hello to everyone,

I'm writing because recently I encountered an issue with my solar system (correctly working untill some months ago) and I hope that someone here can solve it.

My setup is as follow:

- Semi flexible MONOCRYSTALLINE solar panel 105W with this characteristics

V Pmax (V) 20,16
I Pmax (A) 5,26
Pmax (Watt) 105,99
Vca (V) 23.04
Icc (I) 5,63
Eff. cell % 15,42

- Victron energy MPPT 75/15

- Green Power AGM Battery 12V 100Ah

I live in north Italy and the results of a test made today at 2PM are these:

Mutimeter voltage directly out of the panel 19.6V

Current directly out of the panel 2.6A

Multimeter voltage at the end of the cables 19.5V

Current directly at the end of the cables circa 2.6A

The I connected the cables to the MPPT 75/15 (with battery not fully charged 12.8V connected and no loads) solar voltage displayed by MPPT is circa 14.6V, the same result with multimeter directly on the MPPT terminals. Current showed is 0.3A.

So the MPPT doesn't charge the battery..

After that I disconnected the battery from the MPPT and the voltage displayed is 19.2V and 0A.

Fuse is ok.

What could be the problem? Damaged solar panel or MPPT??

Thank you for your answer.


Emanuele D asked
Emanuele D answered ·

2 Answers

Multiplus 12v/3000/120v putting out 80v

Need help trying to figure out multi setup. This is my first install of a battery bank with a inverter/charger. There is much to be learned , so thank you in advance. I installed my multiplus 12v/3000/120v with 2 chins 300AH batteries and have a BMV 712 and Ve Bus dongle to read info. First night testing it was running in inverter mode and did not appear to be charging batteries, but seemed to be letting passthrough power through. I check it in morning and it was flashing low battery ( not sure why it was using battery when shorepower is passing though). So when I switch off battery cutoff multi will have a solid low battery light and no passthrough power is present. I test voltage and get 120v on ac in and 80v on the ac out. I am not even sure where to begin.




etrim asked
Paul B commented ·

3 Answers

BlueSmartCharger IP67 not compensating voltage drop

My IP67 12/25 charger cannot keep a Lithium battery at constant flow/storage voltage. So the battery is permanently discharging and charging again. The problem is varying voltage drop in the chargers wires due to varying DC loads on the boat.

The problem would be solved if the IP67 charger could compensate for voltage drop. Unfortunately sensing battery voltage via VE.smart bluetooth network seems to be currently out of reach, which is disappointing.

My idea to overcome the problem is adding a feature to raise the chargers output voltage as a function of current. On my installation a voltage compensation of 15mV/A would be necessary. It would be great if Victron could add a user configurable setting for compensating voltage drop in mV per A of output current.

rheinskipper asked
mrhappy commented ·

0 Answers

Multiplus-II battery low voltage

I have a very specific battery system, nominal it is 48V, but at its lowest SoC it is 31V. Will the multiplus be able to start charging when the battery is at this point or will it go into error?

floris asked
floris commented ·

1 Answer

Multiplus Not Reading Voltage Sense Wires

I have a 5kva Multiplus connected to a 48v 300Ah lead acid battery bank. There is a roughly 0.8v drop between what battery voltage the inverter sees as displayed on VeConfigure and actual battery voltage. E.g Multi reads 49v whereas battery reads 49.8v when measured with a multimeter at battery and inverter terminals.

I have connected the Voltage sense cables to the appropriate terminals but these seem to have no effect on the Multiplus' voltage readings. I even restarted the Multiplus a few times and no improvement in its voltage readings (still off)

The voltage sense terminals that fit into the Multiplus have ferrules about half inch long crimped on them - I am beginning to think I need longer ferrules?

There is no GX device or BMV in this config as it is a simple backup system. I need a reliable means to read the correct voltage as the low battery cutoff and absorb and float setpoints absolutely need an accurate reading.

neeyee asked
ludo answered ·

6 Answers

BMV-712 Main Voltage Showing 0.02V

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.




ian-doyle asked
phil-marshall commented ·

1 Answer

Functional purpose of voltage sense wires?

Can someone shed some light on the intended functional purpose of the Voltage Sense wires on a Multi/Quattro?

Are you using it? If so, how/why?

The manual says loosely that it's "to make up for voltage losses across the wires".

With the volt sense wires connected or not connected, under minimal load or loads in excess of 100A, I've never seen any change in the reported voltage by the system.

This was true even before my installation of a BMV (with the lithium batts) and still so now, since SOC and voltage readings (I assume) are now coming exclusively from the BMV.

The voltage reported (by the BMV) is within .01 V of the voltage reported by the BMS on the batteries with minimal load, and within the expected 2-3% difference under heavy loads.

I'm using 2/0 (70ish mm cross section) wires and runs are around 10-13 ft to the batteries. The BMV is 5-7 ft to the shunt. 24V lithium system.

The lead-acid system prior was considerably sloppier, although still using 2/0 cable, and I still recall no differences.

geomz asked
ludo answered ·

6 Answers

MultiPlus-II GX - Why is my output voltage not stable - straight line

I would have expected a more stable output voltage. It seems that the output voltage follow the input voltage, is that correct?


z69 asked
Matthias Lange - DE answered ·

1 Answer

MPPT voltage during Dark hours.


Image Caption


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How is it possible to have voltages from the panels, it's pitch blank outside, not even the moon is on the sky.

sebastian-w asked
rickp answered ·

1 Answer

Voltage regulation for sensitive 12 volt electronics

I am trying to determine which Victron product is best suited to manage voltage for some small, sensitive electronics in my van system.

i am looking at the Orion DC DC chargers and converters, but the converters are not Bluetooth. It looks like I could use the 12 12 DC DC charger in “Power” mode.

is there any reason not to use a charger instead of the converter?

kingzrule asked

0 Answers

Battery is not charging anymore?!


I am not sure if it's connected to an update I did, but my Battery is not charging anymore. The Smartsolar is showing me Volt from the solarpanel but no Watt is coming in. In the history the battery minimum is always 0... After reconnecting everything and checking the cables it stays on bulk for 2 Seconds and changing to floating. I will ad some Screenshots, maybe someone can help me???

jonny asked
jonny commented ·

1 Answer

SmartSolar MPPT 150/35 change of system voltage


I used my MPPT on a 24v battery system. Now I changed the battery system to 48v.

The user manual shows that the system voltage can be changed via the app - and I found it there in the settings.

My question is:

Do I need to change the voltage setting from 24v to 48v while the MPPT is connected to the 24v battery - because it's current setting is 24v?

Or can I connect it to 48v and then change the system voltage from 24v to 48v?

This is not clear documented and I do not want to destroy it.

I also already searched this forum without success.

Thx Norbert

norbert asked
RO NISH commented ·

2 Answers

Orion-Tr 12/12-30 max output voltage

I've got a 4S Li-Ion battery bank that I want to charge from the starter battery/alternator. I need the Orion-Tr to output at least 16.4V for an optimal charge.

The Orion-Tr spec (and print on the unit itself) says output voltage 10-15V. However, when I use the Orion-Tr in the VictronConnect demo library, it will happily let me set the absorption voltage to 16.4V. Can anyone confirm what the max voltage output of the Orion-Tr really is? I'm about to order a unit, but thought I'd check in here first. Thanks!

pokerfjes asked
pokerfjes answered ·

1 Answer

BMV712 - Amps vs Percent?!

Hi All,

I just can't figure this out and it's driving me nuts. There are similar posts but never a working solution?

I have two 6v Golf Cart batteries connected in series. 230 Ah. System settings and wiring below.

Victron reports 10.4 amps used, and says that's 97.2% of 230 amps. (is that not 95.4%?)

But when you take their 97.2% of 230, that SHOULD BE 6.44 Amps used?

HOW DOES THAT WORK?! What am I missing here?

What I've done:

- Fully charged the batteries to 100%.

- I then let them let sit for 2 days to stabilize voltages (Completely disconnected all power leads - only thing connected was the BMV 712 - just the little power wire)

- Battery read 12.8v after the two days (The little BMV power wire was still connected)

- I did as the manual states to set zero current:

A zero current calibration is (almost) never needed. Only perform this procedure in case the battery monitor shows a current while you are absolutely sure that there is no actual current flowing. The only way to be sure of this, is to physically disconnect all wires and cables connected to the side of the shunt. Do this by unscrewing the shunt bolt and remove all cables and wires form that side of the shunt. The alternative, which is switching off loads or chargers, is NOT accurate enough as it does not eliminate small standby currents.

- To me, it should not matter the state of the battery when you set Zero Current?

(There is NO current flowing as the battery is disconnected)

Can someone explain it like I'm 5? LOL

So far everything else seems to work like it should, but I'm still confused as to what my battery state really is?

Battery reports full when I believe it to be from the converter (and also the MPPT charger on the solar reports the battery to be full as well)

At the VERY LEAST, what is more accurate, the percentage, the amps used or the voltage?

(So far, I've been following Amps and watching the Voltage reading and trying to make an educated guess that way) Voltage will read 12.1v when the percent still reads in the low 70's? Is that not empty? So confused :(

To me the percentage is so far out of wack that it make ZERO sense. This battery monitor DOES NOT help me monitor my batteries :(



The battery is manufactured by East Penn MFG also called (DEKA) its a GC15.

Two batteries connected in series will be 230Ah. (130Ah useable)

- Reserve Capacity at 25A is 448 Minutes

- RC at 75A is 120 minutes

- The Peukert’s coefficient for most use cases for this battery is 1.24

What is the recommended Bulk, Absorb, Float, Equalize and maintainer parameters?

- Bulk charge to 2.35 volts per cell and hold for Absorption. (14.1v for two in series)

- Float charge at 2.25 volts per cell. (13.5v for two in series)

- To compensate for battery temperature not at 20°C:

- subtract 0.005 V/cell for each 1°C above 20°C;

- add 0.005 V/cell for each 1°C under 20°C.

- An Equalization charge can be done at 15.5 volts.

Max bulk charging current is <=30A per 100 Ah (C20). So for this 230 Ah battery, that's 69 amps. (If charging a pair in series, it's still 69 amps.)




mogal asked
JohnC commented ·

2 Answers

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