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Voltage difference Multiplus2, MPPT100/20 and BMS without load

Hello, is there a way to calibrate measured volltage for Multiplus2 and MPPT100/20

Measured with multimeter without any load on battery I got the same voltage like the BMS.




gesiima asked

0 Answers

Solution for a large voltage drop AC In for Multiplus 12/3000/120


I have installed a Multiplus 12/3000/120 on a sailing yacht and I notice a large voltage drop on the AC In side.

- All cables from shore plug up to AC In are 2.5mm2
- Cable distances are from shore plug to yacht = 15m / from yacht in to Multiplus = 5m
- I have one RCD between shore and the AC In (also one after AC Out)
- Voltage from shore without load is 218V
- Voltage AC In drops from 218V to 205-210V when charging at 90Amps 12V
- I notice a quite large negative power reading on the AC Out (up to -100W)
- When decreasing the charger output to <30 Amps 12V the AC In voltage rises to around 216V and the AC Out power reading rises to around -10W
- When not connected to shore, the inverter gives a normal 230V to the AC Out

You can find a screenshot below of the Victron Connect which shows all figures.

Is this issue purely depending on the Marina I'm berthing (old cabling, trafo issues...) or are there any internal/installation aspects I might be looking into?
Is the AC Out negative reading a side effect of the voltage drop on the AC In?




basile-cools asked

0 Answers

PWM LCD USB 12V 5A : 1.1v voltage at PV terminals while PV disconnected


Equipment : PWM LCD USB 12V 5A + PV victron 30 wc + battery superpack 12.8v lithium.

With the PV (30 wc) disconnected, there is always 1.1V displayed by the "PV voltage display" and by voltmeter measurement of the +/- PV terminals of the controller. The battery is 100% charged. Is this normal? Is this residual voltage coming from the battery?

pgu asked

0 Answers

PWM LCD USB 12V 5A : tension de 1.1v aux bornes PV alors que le PV déconnecté


matériel : PWM LCD USB 12V 5A + PV victron 30 wc + batterie superpack 12.8v lithium.

Avec le PV (30 wc) déconnecté, il y a toujours 1.1V d'affiché par « l'écran de tension PV » et par mesure au voltmètre des bornes +/- PV du régulateur. La batterie est à 100 % de charge. Est-ce que c'est normal ? Cette tension résiduelle vient de la batterie ?

pgu asked
pgu edited ·

0 Answers

SmartSolar charge controller MPPT 250/100 wrong equalize voltage

This seems to be a new problem. I attempted performing a manual equalize. This is of course after being in Float mode and having finished a full bulk/absorb charge. Equalize only uses the absorb voltage. it completely ignores my equalize voltage setting. It also seems to be allowing WAY too much current through. I have my equalize current set at 7%, should be 5.32 amps but it seems to be giving the charge all the amps available, just before the sun is down it's cranking 52 amps in... so is the manual equalize function completely broken at this point? Sure seems to be

Dave asked

0 Answers

800 watts of solar full sun. Victron 150/100 charger controler volts/amps fluctuate


I'm still trying to figure out if anymore mistakes have been made in a Professional install? The last couple days in Quartzite AZ it's been full sun. I noticed in monitoring the Victron app when the voltage goes up the amps from the panels goes down? And it looks like a EKG every second or 2 I see one go up and the other down this continues until the sun is gone. I'm also concerned they didn't wire something correctly because before the solar I had a factory installed 1000 Watt inverter that kept the residential refrigerator going off 2 75 AH lead batteries. These 2 batteries could power the fridge and Starlink for 8+ hour's before the inverter shut down. After having the system for almost a week I haven't been able to get the 2 Battle Born Game changers past 70% on solar only and have had to run a generator for 2-3 hours to get them to 100% before we would retire for the night. I'm seeing 500+ Watts from the 800 watts of panels parallel/serial but should the voltage and Amps be swapping like This? Could this be why I'm not getting a full charge off the solar? I haven't been on the roof yet to check the connections. I found a few oversights already on the ground like the tension reliefs inside the Multi plus II were not tightened at all leaving the 120v wires are risk of coming loose from vibration during towing of the camper. What should I look for that could be causing this? I'm not going back to the place it was installed at the guy who worked on this part of it cops and additude when I find mistakes I bring to there attention. They even tried to keep parts I needed like the termination jacks. So I'm just going to have to check everything myself and fix it. You can see how much power I've generated over the past few days. The only thing running is the fridge, a TV , small Roku on the TVs USB power and a Starlink. The Starlink maxes out at 80-90 watts, the fridge 200w when running and the TV about 60 watts. Maybe I just need a few more panels? Sorry it's so long I don't know how else to explain what's happening after dropping $15k I should have done it myself.

saboken asked
klim8skeptic commented ·

0 Answers

BlueSolar HUGE Drop in VBUS battery voltage on morning startup

2x Multi 3kw - 4x Pylon US2000 - Bluesolar and SmartSolar MPPTs - Off grid system.

This morning, from the logs, around PV wakeup time, the VBUS battery voltage dropped to 36.42v from a nominal 47v - SOC was good at 40%

BMS voltage was reporting good however, at around 48.5v

Minimal AC loads. cica 140w - which was consistant overnight.

VBUS voltage suddenly dropped then caused inverter to cut out as you would expect.

After a reset and time to recover - system appears to be working as expected.

What could cause the drop in VBUS battery ? - seems to align with the BlueSolarStartup which is a south facing array.

Possible signs of an early failiure ? or DC PV string issue ?

Chris asked
Chris edited ·

0 Answers

Centaur 12/30 voltage output without load

Hi community, I hope you can help me with a basic question about a Virctron Centaur 12/30 battery charger. I have it on my workbench for repair. The reason that i have it is because a friend of mine connected the battery he wrong way. I had to replace a Schottky diode 30CTQ045 and now I want to measure the output voltage without load but the output voltage is less then 1 volt. Does the battery charger have to provide always a 12 Volt output? Or does a battery actually have to be connected to it?

Hope you can help me out?

Thanks in advance for your assistance.

Wim (The Netherlands)

Wim Schaap asked

0 Answers

High Voltage Alarms from VE Shunt

I have a newly installed system with a VE Can Shunt and a Cerbo GX. Overnight the system logged two high voltage alarms, one of 14.18v at 2am, and a second of 13.16v and 1pm on a sunny afternoon. I am charging 400ah of lithium, have the charge voltage on the MPPT set at 14.2V. The boat is not plugged in so the AC charger on the Multiplus was not active. A fidge and frezzer were turned on which combined draw about 10amps. Is this a settings issue or something else?

Tim Armstrong asked

0 Answers

Multiplus II - Transient Load causes low bat shutdown

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,


ralphd asked

0 Answers

Low Voltage Alarm goes off earlier and earlier

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?

helgamarie asked
klim8skeptic commented ·

0 Answers

multiplus 12/3000 voltage reading to low


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.

lars78 asked
lars78 edited ·

0 Answers

Output voltage of the LOAD Output on 75|10 controller


I read that the output voltage of the LOAD Output on a VictronEnergy MPPT Bluesolar 75|10 controller was the same as the output voltage of the battery. I plan a 12V Battery to the controller.

My question is : is the LOAD voltage output always 12V (as long as the battery is charged enough) or is it the same as the battery (which can vary between approximately 11V and 14V, depending on the mode) ?

Thank you for you answers !

agarreau asked

0 Answers

SmartSolar 75/15 low voltage under load

Hi There

first off thanks for reading my question, and thank you in advance for any answers that come through.

What was working perfectly fine now is not, and any attempt to run load from the “Load” terminals on the SmartSolar controller fails. Without any items turned on, the available voltage is 13.4v. As soon as you turn on something; a light, usb charger, etc; the voltage drops to 9v and renders the available power useless. I have a 12v 90w laptop charger. Plug that in and voltage drops to 4-5v.

the setup is as follows:

  • I’ve converted the kids cubby house to an outdoor office
  • 200w solar panel
  • SmartSolar 75/15
  • OMP 12v, 25a circuit breaker for each circuit. PV - Battery - 12v Load - 240v/500w inverter
  • Everything is cabled with Narva 50amp rated cable
  • 50Ah LiFePO battery
  • 12v load consists of 3 LED lights, usb charge ports, and 12v power sockets. This is connected to the Load output on the smart controller
  • Inverter has its positive connected directly to the battery, with the negative connected to the 12v load circuit so that in the event of the low battery, the circuit will cut out - as per the instruction manual.
  • Inverter is for a 32” Samsung Smart monitor.
  • 12v load and inverter are connected to a common ground bus.
  • As per instructions, PV is not on the common ground
  • Inverter power is not affected as it’s powered directly with battery
  • PV charging seems unaffected suggesting it’s specific to the Load component of the controller
  • Peak amperage is around 13amps

troubleshooting tasks already undertaken

  • Charge battery with mains powered car charger.
  • Swapped OMP circuit breaker from load with Inverter circuit breaker. No change
  • removed positive wire from load terminal on the controller and connected directly to battery. All other wiring unchanged. This resolved the problem and suggests a problem with the controller. Am currently running this setup for a number of hours and seems to be fine
  • Reset controller to factory defaults
  • Disconnected and reconnected all power to controller several times
  • According to the app, I have the Latest firmware versions installed v1.59
  • Battery setting set to always on
  • Jumper removed

Keen to hear of any other troubleshooting I should do or if you think the controller has a fault.


thanks again.

bilmcla asked
kevgermany commented ·

0 Answers

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