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battery system voltage

Different voltage between VRM and battery

I have connected the power of a Venus GX on a service battery and also a multiplus. Now I see on the VRM Website (monitor) a voltage of 9.6 Volt but my service battery has 12.5 Volt. Why is there a difference between the VRM monitor and the real voltage of the service battery?

sijtze-de-boer asked
seb71 commented ·

2 Answers

Help needed regarding a little water turbine


I have a water turbine that is used to power a small kids shack ventilating fan next to a river, the input from the turbine is 2A (fluctuates), 12v. Will any of the charging control module for solar work for such an application? The load is 1.5A and I am planning to use a 12 V lead battery.

nour-akel asked
nour-akel commented ·

2 Answers

Victron Phoenix 12/50 Resistance values

Hello together,

is it possible to get the values of the Resistors?

my Charger get up to 16,X Volts and like seen on the Picture, there are 3 burned resistors.

i dont know if the resistors are the reason or the impact for the problem so in first step i want to change the burned ones.

Kind regards



visual asked
jack2006 answered ·

1 Answer

Other than changing inverter to 24v . Is bigger wire the only option ?

Hello, I have a victron

12v 3,000 watt inverter .

My houseboat is all electric

My big appliances are always at low voltage.

To low. The wire from batterys to inverter are .50 . I have 8 100amp batterys and 4 200 watt panels. The distance from batterys to inverter to circuit breakers are maximum 1 meter away for all.

What can I do to compensate low voltage other than purchasing a 24 or 36 volt inverter ? Cheers, John Payne

catweasel11 asked
alan edited ·

3 Answers

How to properly set charged voltage on BMV-712?

We have 2 x 6V 224Ah batteries in series hooked to a WFCO converter and while the converter/charger's bulk voltage is 14.4V (which it only enters after deep discharge), the absorption voltage output on this charger is only 13.6V and float is 13.2V. Meanwhile, my parallel solar charger (Victron 75/15) is set to 14.4V absorption and 13.8V float. Does this mean that the battery will only be fully charged if I have solar charging present? And if so, I'm wondering how to properly configure a BMV-712 monitor in terms of "charged" voltage - if I use 13.2V then the monitor might think the battery is full when it's not, but if I use for example 14V, the monitor may never show a full battery if I'm just charging off the converter (ie. Cloudy day / no solar).

Thank you for your help!

Tomasz Czernecki asked
JohnC commented ·

3 Answers

OCTO GX - 4 BlueSolar MPPT - system voltage issue

Hi there

I have 2000W solar through 4 BlueSolar MPPT's 3x30 1x60amp with VE Direct cables to my Octo GX, also connected is my 12/3000/120 Multi.

Batteries are 2x RB300Ah Relion lithiums.

I have a BMV712 smart also connected to the Octo via VE Direct.

I am having the same issue as many with the MPPT battery voltage being different to the BMV voltage, I can see my controllers going to float as low as 70%SoC.

I have been told if I instal a Bluetooth sensor to the battery bank and network it to the BMV712 that this will become the default voltage for the entire system, has anyone done this with an Octo or can confirm it is correct.



Wayne asked
Wayne answered ·

3 Answers

High voltage alarm when voltage looks ok


BMV has been triggering high voltage alarm over the last 24 HRS yet I see battery voltage to be normal


Jairus Onsafari asked
Jairus Onsafari commented ·

2 Answers

Could wrong voltage from MPPT 100/50 damage super pack battery?

Good day to you all,

I have installed the following:

Solar array : 800W (Voc 43V)

1x MPPT charger is 100/50

1x Battery: Super pack 25.6V

The system worked well until, the battery was fully discharged and low voltage protection activated.

Than the MPPT couldn't start recharging the battery again. Voltage at the battery was 14.7 V with solar panel input (in float mode), and 0V without.

I discovered later that MPPT voltage auto detect was the issue, and changed the settings manually to 24V using the app. It looks like its working. I am waiting for another blackout to see it MPPT remember that setting.

My question:

Could the prolonged application of 14V (see in red below) from the MPPT on the battery had done some damages to it? Knowing the battery is not supposed to go below 20V.

Thank you for your inputs



Days ago Date Yield(Wh) Max. PV power(W) Max. PV voltage(V) Min. battery voltage(V) Max. battery voltage(V) Time in bulk(m) Time in absorption(m) Time in float(m) Last error 2nd last error 3rd last error 4th last error
0 12/9/2020 0 220 42.07 0 23.8 3 5 225 34 0 0 0
1 12/8/2020 0 1 42.89 0 14.78 0 3 518 34 0 0 0
2 12/7/2020 0 2 43.65 0 15.1 0 3 260 34 0 0 0
3 12/6/2020 0 2 43.65 0 14.91 3 1 341 0 0 0 0
4 12/5/2020 20 3 43.91 0 14.78 0 2 802 0 0 0 0
5 12/4/2020 1120 615 43.65 0 28.66 419 90 290 34 0 0 0
6 12/3/2020 1870 811 42.86 25.38 28.7 416 64 314 34 0 0 0
7 12/2/2020 490 568 43.65 0 26.25 228 4 198 34 2 34 0
8 12/1/2020 0 2 43.09 0 14.84 1 3 494 34 0 0 0
9 11/30/2020 0 1 44.44 0 17.14 1 1 616 0 0 0 0
10 11/29/2020 2100 803 40.75 0 27.35 808 0 0 0 0 0 0
11 11/28/2020 2480 845 41.68 24.23 28.52 781 7 17 0 0 0 0
12 11/27/2020 2000 800 43.55 24.5 28.67 540 9 265 0 0 0 0
13 11/26/2020 2820 693 41.42 24.45 28.5 760 50 0 0 0 0 0
14 11/25/2020 2360 770 43.55 24.48 28.74 494 90 220 0 0 0 0
15 11/24/2020 2460 843 42.42 24.58 28.5 535 18 251 0 0 0 0
16 11/23/2020 2270 881 43.26 24.52 28.63 588 80 132 0 0 0 0

nicomauritius asked
nicomauritius answered ·

2 Answers

Best float voltage and absorption time ("Energy Unlimited book)
  1. good morning, I have read (not all given my difficulties with English ....) the book "energy Unlimited", and I have a couple of questions.
    I live in a camper with a 300 watt PV system, 30 A mppt regulator and 2 service batteries (1 + 1 or in parallel, Agm 100 ah and cheap start battery 100 ah) and an engine battery.
    The AGM is almost 3 years old and 900 cycles and still works almost at 100%, the start battery for the services was replaced after 2 years and 700 cycles with another similar one.
    I think I use them in the best way:
    Absorption at 14.4v and floating at 13.7v, with temperature compensation with sensor on the battery.
    The average working temperature is 25 degrees Celsius in the Canary Islands.
    My Tracer 3210 regulator is great but has an adjustable but fixed absorption time. Default to 120 minutes.
    However, I copy the algorithm of the victronenergy regulators.
    If I discharge the batteries in the evening, for example Vb> 12.6, I set 1 hour of absorption.
    If 12.2 <Vb <12.6, I imposed 2 h of absorption, etc ...
    The average discharge each night is at 12.55 v.
    However, while reading the book, I had some doubts about the float voltage.
    The book says that a 13.8v float for a long time damages the batteries due to excessive gasification ... especially the VRLA batteries.
    My batteries on average float from 12.00 / 13.00 to 17.00 / 18.00 (more time in summer, less time in winter).
    The alternator supplies 14.2 v and I connect it to the service batteries with victronenergy cyrix, almost only at night while traveling or traveling in the rain, for the fridge etc. So it's not a problem.
    In your opinion, what is the best absorption voltage compared to the usage data I have provided?
    For now I have lowered from 13.8 default to 13.65.
    If I took it to 13.2 / 13.4 v would I get some advantages in battery life or some disadvantages?
    Thanks and I apologize for the length.

francesco asked

0 Answers

Limiter for absoption voltage

I have a question about absorption voltage.

My question I about MultiPlus.

In VE Configure I can change the Temperature compensation. If I set the compensation to -15.6 mV/deg, I will get a maximum abs. voltage at 15.5V. This is what my battery supplier recommends, as max abs. voltage. (Tudor/EXIDE TR350/ER350, lead acid) But they also recommend me to set the temperature compensation for -30mV/deg.

Their reason for a max abs voltage around 15,5 is that equipment in the boat can be damage with higher voltage.

So, to my question: Is it possible to change the max abs. voltage after temperature compensation, or just put a limit. I still want 14.8 V at 25 deg.

I just remember that this, also applies to my SmartSolar 75/15, but this is in another boat. (But same battery)

palle asked
klim8skeptic commented ·

1 Answer

Pylontech abnormally high voltages after 2.60 update


After more than one year of perfectly stable operation with a ESS system comprised of a Multi-II 5KVA and a MPPT 150/100, 2x US2000B Venus OS 2.60, always in keep batteries charged mode, (for back-up for critical appliances) we've been experiencing random high and low voltage alarms from the system, which are unusually high (almost 54VCC sometimes). No LED alarm whatsoever on the batteries. DVCC is activated, SVS is off, MPPT in slave/BMS controlled.

We're trying to figure out this for two weeks now, we're in touch with Pylontech but so far they're not giving us conclusive answers. We've changed the battery monitor from "automatic" to "Pylontech Can.Bus" today to see if it changes anything. One explanation might be that they're not designed to run under a 100% SOC for extended period of times and thus might be internal cell imbalances that are not corrected as they're not discharged and cycled. Anyone can chime in ?

Thanks in advance,



perma-batteries asked
Guy Stewart (Victron Community Manager) commented ·

5 Answers

I measured 50V on a 24V system. How does that work?

Shema 50V problem.pdfI have a strange problem on a ship with a 24v system. When checking the electrical system, I found that if everything or Multiplus, MPPT, etc. is connected, apart from the negative consumer and the starter battery are also connected to the system, I can measure 50V on the negative cable of the consumer and the positive pole of the consumer batteries . If I remove the plus of the starter batteries, I measure normal about 24V. I don't think that's normal and it looks like a hidden series connection to me. If EVERYTHING is connected, the system has normal 24V and the 50V are no longer visible. Maybe I'm making a mistake and don't see the forest for the trees. Does anyone have any idea why that is?

Robert M.O. Seidel asked
redtute answered ·

3 Answers

Help me to understand Voltage drop ( decrease ) while under load vs at rest and state of charge

I was wondering what is the true reading of a AGM battery under a heavy load ( 150 watts)

The manufacture of my battery says the halfway mark is 12.4 volts ( 50% ) When I power on my television, I keep it on until it reaches 12.4 but then the voltage increases back up to 12.65 after it’s turned off

I guess my question would be this- would the 12.4 constitute a true halfway mark when running the television because of voltage decrease under a load ?
Or is it safe to run it lower than 12,4 if it bounces back to 12.65 ?
I have noticed that Victron records the lowest number under a load even after it bounces back up.

dallas asked
spirou commented ·

1 Answer

BVM-702 Voltage reading inaccurate

Hi all.

After reading all previous questions and answers associated with my issue I still cannot find a fix for my problem.

The BVM is mounted very close to the 24V battery (30cm) and connected with 35mm2 cable. The MPPT regulators are 100cm away and connected to the battery via 16mm2 cable.

The issue regards the inaccurate voltage reading on my BVM-702 as it does not agree with my two digital multi-meters nor my two Victron MPPT charge controllers. The BVM is consistently showing 0.8V lower than all these other devices.

I have tried replacing the in-line fuse on the BVM with a larger 1A fuse and even joined the wires together to bypass a fuse completely but the low reading is the same.

When measuring battery voltage using my meters, it makes no difference if I measure from the negative pole of the battery bank or either posts on the actual BVM shunt.

I tried replacing the communications cable from the shunt to the display just because I was running out of ideas........but it made no difference.

My final attempt at a fix was to swap out the shunt for a completely brand new one which I was able to borrow but unfortunately there was no change.

Any ideas very much appreciated

wishful-thinking asked

0 Answers

Victron 100/30 Voltage Settings for Winner Solar SMF


i have two Winner W280S (280Ah) as a Strip to get 24V for my inverter. Now i want to make a Profile for the correct Voltages for charging them both. Here are the voltages that Winner says they should be:

- Bulk 14,8V

- Absorption 15,4V

- Float 13,7V

so, i think i take them all as 2x. But whitch one is the right one in the profile? There i have:

- Absorption Voltage

- Float Voltage should be 27,4V

- Equalisation Voltage

Thanks a lot for your help!



solalasolar asked
solalasolar commented ·

2 Answers

Voltage Sense Wires using 2 Multiplus Inverters

I installed Voltage sense wires to my battery bank on the L2 or slave inverter and it does not seem to be seeing the difference in voltage that the batteries are at when under load. It still appear to be getting its info from the inverter cables. Do I need to enable this somewhere or does it need to be connected to the master inverter?

rjoustra asked
Matthias Lange - DE answered ·

1 Answer

Help Requested...Voltmeter doesn't match Victron products

I own a Victron MPPT and a Smartbattery Disconnect. I've tried Victron CS on several occasions to help me with my below problem; with the typical "no response" (Victron you should work on your customer service). My dilemma is this...

Both items listed above read in the 13.x volts when I charge my LiFePO4 12v batteries. The "read" is coming in on my BT Victron app. HOWEVER...when I put a voltmeter on each battery I get a reading for each battery as full (14V...ish). I know this is correct as I just charged them.

With that, I've tried to factory reset on both Victron items hoping that would resolve the issue. It didn't. What am I missing?

Thanks in advance for everyone's help.

captain-spear asked
Justin Cook - Bay Marine Supply USA answered ·

2 Answers

CCGX high battery voltage alarm


acdc-hansi asked
Matthias Lange - DE answered ·

1 Answer

MultiPlus. input voltage 66V DC

Hi. I have a 48/3000 multiplus. In the technical book it is written that the maximum input voltage = 66V DC. But when it reaches 64.7V it stops. How can I adjust it to work up to 66V. Thank you

ciprian-dobrescu asked
ciprian-dobrescu answered ·

2 Answers

New Batteries: Low voltage despite low usage


I just installed 2 new Duracell AGMs (100ah) in my camper. I reset the history on my BMV700. Watched a few hours of TV last night, ran the water pump a few times. Wake up in the morning to my batteries at 12.24V.

BMV shows SOC at 94% and only used 19AH. Why is my voltage so low? Did I get bad batteries?

leavenotrace asked
schlanbusch answered ·

1 Answer

MPPT 75/15 not stopping charge, high voltage alarm

I have rather simple system, I think, for my van. Trying to charge a house battery from solar and vehicle battery. For now I am just trying to get the Solar to work independently ( leave the DC/DC charge out of equation for now). I have looked at the Victron Van concept, which is much more over complicated in comparison to my setup. So I am having troubles understanding the schematic I need.

The MPPT keeps charging the battery well past 13.2V. (I recently changed this down from 13.9V, but it didnt help) It will continue on up towards and past 14V, then battery will read "Busy" , fully charged and stop taking charge. Then it sends a Over Voltage Alarm, referring to "Allow-to-charge contact"

What stops the MPPT or DC/DC from charging when the battery gets fully charged? Do I need an additional Battery Protect? I am not sure if I am missing equipment or have the wrong settings.

All Victron equipment:

12.8V 100Ah LiFePo4

Smart Solar MPPT 75/15

Orion Tr Smart 12/12-30

Smart Battery Protect 12/24-100 (1)

BMV 712 Smart


Lynx Distributor 1000 ( which I dont think I even need)

Solar Panels

2 - 100W Renogy







mbrun asked
spirou answered ·

1 Answer

Mobile studio rig, 120v to 230v

I own a Mercedes Sprinter with a Volta Power Systems 13.5kWh rig. It's being used for mobile sound recording. Wanna put a small 6000btu Mitsubishi MUZ-FH06NA in it, powered off the 120v supplied by the Volta batteries. Can I use the Victron autotransformer 120/240 32a? If not, what would be the best way to accomplish this?

dylanwest99 asked

0 Answers

Not reaching SOC limit

My system uses the ESS assistant and would normally discharge to the "minimum" or "active" SOC limit. Currently, this is at 30% for both. However, in the last month or so, the system is only reaching 38%, even if I switch off-grid. It seems to be switching at the sustain voltage (50v). The battery seems to be healthy and it's BMS is not giving any error. Also, the battery is charged to 100% every day. I even kept the batteries charged for 3 days but when trying it this morning it switches again at 38%.

Is this a setting issue (which has not been changed) or a battery issue? Or should I be checking something else?

adrianc asked
adrianc commented ·

1 Answer

Lead Crystal Battery Settings with BMV-712

Guys need help with a Lead Crystal Battery that I have (spec supplied) do I set the same as a AGM battery with my BMV -712 Smart?

Tony Alba asked

0 Answers

SmartSolar battery voltage spike

I have a SmartSolar 250/100 mc-4 with 3 280W panels connected to it. All goes to a 200 ah 12v lithium battery. Today I experienced voltage spikes from 13.9 to 26v and back multiple times. It burned my inverter and the house almost caught fire. What is the cause? Anyone?

roman asked
kosio86 answered ·

2 Answers

Battery 712 monitor showing slightly high voltage?


Have just installed a 712 battery monitor to 12v battery bank. Voltage seems to be showing a little high?

Peter Groves asked
Matthias Lange - DE commented ·

3 Answers

BMV 712 Smart Monitor dosnt work


Hey ,

I have Problems with my BMV 712 . Im Sure that i haf install everything correct, but the Monitor dosnt work.

Energy flows.

The battery Pol of the Shunt is connected with the minus Pol and the load Site of the Shunt is connected to the System ground.

+B1 -> Battery1 +, +B2 -> Battery2 +

I send the Monitor back, but the seller says it Works. He Send another Shunt, Same Problem ...

I Switch the phone cable, still nothing.

I tyried ist with other cables for the +B1/B2, also nothing.

now i Test the „Energy Flow“.

Shunt - to Shunt +B1/B2 has no Connection, i was mit able to get the 12.8V.

Anybody and idea ? What did i wrong?

Sorry for my english, thanks for help !



northernlightss asked
northernlightss commented ·

5 Answers

Help!!! Battery alarm.

Installed solar panel Saturday. With mppt 100/50 and bmv712 plus 1200w inverter. Everything was working fine yesterday. Now I can’t connect to controller Bluetooth, and the battery alarm has gone off saying charge?? There is nothing turned on ??? I’m worried I will damage something please help!

assimo asked
Paul B answered ·

1 Answer

How to correct or repair a BlueSolar MPPT 150|35 that is reading battery voltage wrong

I have a working installation of a BlueSolar 150|35, v1.16, connected to 2 parallel series of 3 250W/24V panels. The battery bank consists of 5 pairs of 2 batteries, each battery a 110VA 12V stationary battery. The system has been working for almost 2 years without any problem. Four days ago, this changed:

- the system did not have power anymore to run a water pump

- because the battery voltage was too low, about 22.5 Volts

- the MPPT was stuck in 'float' mode really early in the day and because of this, never charged to batteries

Yesterday I managed to (re)connect the MPPT to a Linux machine using the VeDirect RS232 connector. Connecting using minicom, baudrate 19200 and 8bits, I got data frames from the MPPT, below a copy of one of them:

PID 0xA04B
FW 116
V 27320
I 300
VPV 101460
CS 5
H19 159940
H20 36
H21 723
H22 23
H23 400
HSDS 314

This tells me, that the MPPT thinks that the battery voltage is 27320 volts. One minute after seeing this, I measured the battery voltage using a multimeter. Battery voltage is 23,3 volts on the multimeter. The MPPT software seems to stay in float, because of the high voltage it measures.

What are my options ?

- is there a way to re-calibrate the voltage measurement of the batteries ?

- is it safe to re-configure the treshold voltage, set it to a higher value, like 30 or 32V, in the hope that it will go to float when the battery actually has 27 or 28 Volts ?

wiebe-ruiter asked
wiebe-ruiter commented ·

3 Answers

Victron MPPT 100/50 - Batteriespannung falsch angezeigt


Wir haben einen kleine Inselanlage mit 2x 100A 12V Batterien

Dabei mussten wir nun folgendes feststellen: es wird beim Regler eine viel niedrigere Batteriespannung angezeigt als tatsächlich auf der Batterie gemessen.

Dies hat meiner Meinung zur Folge, dass die Batterie obwohl voll immer weiter geladen wird. Bin ich richtig der annahme? Ausserdem hat die Batterie bereits stark Schwefelig gerochen, weshalb ich nun alles deaktiviert und abgesteckt habe.

Kann mir vielleicht jemand erklären, weshalb dieser wert falsch im Laderegler angezeigt wird? Die Batterien sind mit nem halben Meter Kabel verbunden

Ich sag schonmal danke



domsn asked
Matthias Lange - DE commented ·

3 Answers


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