ups Image


Can anyone explain the watts anomaly in the attached image: UPS plugged into inverter?

Can anyone please explain what might be causing the following:

I have a 12 V to 240 V pure sine wave inverter (1000 W); for purposes of experimenting, I have placed a measuring device between the load and the inverter's AC output

If I plug a 60 W incandescent lightbulb into the socket, 60 W is displayed on both the inverter's display and the measuring device.

However, when I plug-in a (small) fully charged UPS unit into the same socket, a load of 48 W is displayed on the inverter and 18 W on the measuring device.

If I plug the same UPS into the mains, the measuring device equally displays 18 W.

Any ideas why there is a 30 W difference?

Best regards


bazil asked
kevgermany answered ·

2 Answers

Quattro Transfer time


I am trying to find info about Quattro 48/15000 transfer switching time (specifically when the UPS feature is OFF):
- What is the switching time when switching from Generator to inverter and when switching from inverter to generator?
- Is the switching different in a 3-phase connection? and in a parallel connection (2 Quattros/phase)?

- is the switch time affected by load, temperature, or any other determinant?

power-consultant asked
janieronen commented ·

2 Answers

Quattro 24/5000 UPS not functioning from Grid to inverter

Hello all,

I am new to the forum but not new to inverter equipment. I have recently replaced my older inverter on my boat with a Quatto 24/5000 with GX unit, MK3 and 2 x 100/30 solar chargers connected to 6X 200 W panels.

The difficulty I am having is the unit has a delay when switching from shore power to inverter. I loose the clock on my microwave and if I have any loads on they stop until the inverter picks them up. I have enabled UPS function as per below. am I missing something?

Up date.... it only happens during loads like the water maker or when the microwave is on. When there is very little load like PC it works fine.

Thanks Steve


screwdriversteve asked
soren-dynamicmill answered ·

1 Answer

Using a multiplus as a UPS long transfer time 10seconds

I'm trying to use Multiplus as a UPS but have a problem with the transfer time. I have read documentation and forums and all state that Multiplus can do a transfer in 20ms when the GRID drops out. However, I am experiencing a transfer time of 10 seconds instead of the expected 20ms. I cannot understand why there is a pause when the transfer occurs from the Grid to the battery, causing a delay before the inverter is activated.

soren-dynamicmill asked
soren-dynamicmill commented ·

5 Answers

Does the Victron system perform full UPS function?

I am new to this and my system was only commissioned at my holiday house a few weeks ago. My setup currently runs on solar all day (unless the weather is bad) and battery all night (unless the battery drops below 40%) other than 300 watts per hour of grid power. If the gird fails, my circuits which are designated as critical loads will run from the battery and 40% of the battery will give them around 8 hours. It appears to me (based on a few weeks of monitoring) that the system will be on “grid only“ power for about 10% of the time (presumably more in winter) and probably increasing to about 60% of the time when we are actually using the holiday home.

My understanding (and I may be wrong!) is that the system will protect from poor quality power (surges, high voltage etc.) from the grid when the battery is in use and when the solar is in use but not when the power consumed is “grid only”. Assuming this is correct, is there any way to protect the critical loads from dirty power all the time using the system or does one need a separate stand alone UPS?

Thanks in advance from a real newbie!

sa-victron-user asked
soren-dynamicmill commented ·

4 Answers

Multi II not Working as UPS (ZA)

Recently purchased and installed MultiPlus-II 48/8000/110-100 with Freedom Won 5.5 kWh battery all connected by a Cerbo. All Victron firmware is latest, v2.94 and 502. (I don't yet know how to check/update the Freedom Won firmware; I'm in communication with the company.) Settings as given on, except that for a while I had the ESS mode as Keep batteries charged rather than Optimized (with BatteryLife).

When set to ZA grid, the Multi correctly acts as a UPS when I kill the AC in at the breaker. However, the Multi shuts down and restarts during a loadshedding event. This behavior seems to be seen elsewhere, and and; people seem to say that the problem is that the grid fails too slowly, more of a brownout where the voltage drops, but not very quickly.

Following the suggestion of some of the above links, I changed the grid to Other and manually set the AC low cutoff to 215V. For the most recent loadshedding event, the Multi shutdown and threw a Low Voltage battery alarm (at 55.84V (?)). Prior to the loadshedding event, AC out draw was low--max could've been 2kW but was likely more like 250W.

I have two questions: 1) in, @Daniël Boekel (Victron Energy Staff) suggested changing the grid code to None (and thus no ESS). Since tells me explicitly to use ESS, should I change settings to try grid None and no ESS? 2) are there other idea(s) for thing(s) I can do to get the Multi + battery to work as a UPS during a loadshedding event here?

Thank you very much for your help!

EDIT: I see that when loadshedding hits, I get simultaneously a Low Battery L1 and High DC Ripple warning/alarm. Also, adding from a comment below, the system shuts down even on very low loads, most recently when the load was only 108W.

zebrainmotion asked
martin-delp commented ·

3 Answers

Bridging the time on a switching station - any suggestions to an alternative to UPS ?

I have a switching station with primary input via solar and 240 V inverter; the secondary input uses the house mains.

In order to 'bridge' the time in switching from the primary to the secondary input I use a UPS for sensitive devices (e.g., computer, router, etc.).

The UPS constantly draws some 100 W irrespective of what devices connected to it are in use.

Could anyone please suggest an alternative to the UPS with less of a load in order to bridge the time?

Best regards

bazil asked
bazil edited ·

1 Answer

Multiplus UPS and mains pass trough functionality? Lack of documentation?

Hi, does all the multiplus models have UPS functionality and mains pass through? And where in the documentation is this mentioned? Specifically for the 12/1200 model.

kokaruu asked
JohnC answered ·

1 Answer

Multiplus 24/1200/25 switching between charger and inverter

I have a Victron Multiplus 24/1200/25 hooked up to a set of series parallel Blue Nova BN13V-108-1.4k lithium iron phosphate batteries. I also make use of a Victron Battery Monitor BMV-702. I use the Multiplus as a backup/UPS to provide power during power outages at my house. I observe the following behaviour of the Multiplus:

• When AC power is lost, the Multiplus switches to the inverter and provides power, as expected.

• When the AC power is restored, the Multiplus starts charging the batteries, as expected.

• After a few minutes, the inverter will kick in again, and the fan will spin up.

• After a few seconds, the fan turns off, and the charger starts charging the batteries again.

• After a few minutes, the inverter and the fan turn on again.

• After a few seconds, the charger turns on again, but this time the fan remains on. The charger and fan remain on until the batteries are fully charged.

• Once the batteries are charged, the fan stops, and the charger goes into absorption mode.

This pattern consistently repeats itself each time the AC power is restored. This happens even if I unplug the Multiplus, and plug it in again after some use (ie, without an actual AC interruption from the utility). Is this pattern of switching between charging and inverting expected each time the AC power is restored? I would expect it to switch to charging only once, once AC power is restored. If this pattern is not expected, what could cause this?

frodob asked
frodob answered ·

6 Answers

Victron MultiPlus II - ESS - Irregular Transfer Time - Appliances switching OFF

Hi All,

Our company has executed over 300 Victron installations and just recently we are encountering a phenomenon where a few systems are not transferring seamlessly from a grid-connected state (ESS) over to the Inverter upon failure of the AC Grid supply.

Victron MultiPlus-II including MultiPlus-II's in parallel
Victron Cerbo GX
Carlo Gavazzi Grid Meter (ET112 or ET340)
Grid code: NRS-097-2-1 (South Africa)
LOM: Enabled (Type B)
Assistant: ESS
Battery: Freedom Won LiTe Home or Pylontech
Firmware: 494, 495, 496, 497

The VRM advanced section does not detect a drop in the AC-Output voltage, however the phenomenon is clearly evident on site where the lights, WiFi router, TV and other plugs will drop and recover - having to reboot as a result of the duration of the power interruption.

We do not have the equipment to measure the output and confirm the transfer time but it is my understanding that the MultiPlus-II is supposed to transfer within 20ms to justify it's proposed UPS rating/capability?

Has anybody got any insights into this problem?

Thanks in advance.

Nicholas Herbst asked
mike-moody commented ·

2 Answers

Inverter mini power cut / power loss for seconds / Ups not working

Good day,

I have a 25kva Generator running a 10kva Multipluss II with 10kwh of battery capacity.

the system has been running ok unto Christmas, (4 weeks)

I have tried to replicate it by starting and stopping the generator and under different loads,

however it seems to happen without any 'Trigger'

I have attached the Excel file showing when the power blip happens i have a loss of data on the Logging on VRM Download.

the generator is used to power the home and when the builders come in the site as well,

however it is only connected via a 32a plug, (and its been working with a current limit of 30a set)

i have the issue sometimes were the ac input is not accepted, even when it is at 52hz and at 233v, however i have linked this to when i do a ve config upload, i have to re-set the ve bus to not have this issue.

batteries are bms connected to the cerbo, and they don't have any issues i can see, I have tried to run the system without the bms connected as well. and have no issues except the 15s power blip, which is still random,

any help would be appreciated, (the attached is all i have been able to get to prove it happens, prior to this I didn't really know if I believed the client)

time today 08.01.23@ 15.41

gen snip 1.PNG

gen snip 2.PNG

gen snip 3.PNG

gen snip 4.PNG

Matthew Deal asked
nickdb commented ·

2 Answers

Slow UPS on Multi ii 5

Hi guys.

Installed a new Multi ii 5 yesterday and UPS is not working as it should. Power goes down for a second before turning on.

UPS function is enabled.

RSA Grid selected.
LOM enabled

Firmware 481.

10kWh FreedomWon installed.

Any idea what might be causing this?


mauromartini asked
Matthew Walsh answered ·

4 Answers

UPS design with Victron

I had Victron for short time, but then was forced to dismantle the units and replace with other system. There is no Victron support in my country and also for this reasons installers does not want to install Victron. As my current system is significantly underperforming (but reliable) I'm searching to have again power that is closer to my needs, but with reliability of current solution.

Maybe someone able will be able to help. I would like to build UPS like install with battery, ideally charged by solar cells. There is cca 8kWp on the roof, battery I would like to have cca 10kWh and maybe also with generator. I need 3phase 240V minimum 5kW per phase.

Known prolems with Victron units:

1. Random shut down with "unknown error" message and also shut down all other units

2. By shutdown grid is disconnected

3. Long transfer times when grid fails causing shutdowns

4. Discharging battery under minimal SOC

5. Extra loud (mainly during night when charging batteries depleted by point2) on full power

I heard that Victrons are used on boats in large scale. How it is done that unknown error does not power down whole ship.

What I had was 3x 5kVA multiplus, BYD battery, 2x MPPT charger, very powerful but not reliable

What I have now is GoodWe 10kW + Pylontech, very reliable, but greatly underpowered and no scaling possible

peter79 asked
Matthew Walsh answered ·

2 Answers

Can I use a Blue Smart IP65 12/15 in an online UPS setup?

Hi. We're currently experiencing some hectic "loadshedding"/planned power outages (few times per day for 2-4 hours at a time) and I'm trying to make my backup power solution a bit more convenient.

Initially manually switching my workstation + internet devices over from grid power to my battery+inverter setup was fine, but having numerous loadshedding slots every day is annoying and I don't think it's the best for these devices to lose power and start up all the time.

I was thus wondering if I can use my Blue Smart IP65 12/15 charger as a power supply for my workstation permanently. So basically creating an online UPS solution (charger => battery => inverter => appliances).

Regarding the power supply function, yes I understand that it has a power supply function, but that's not my question. I want to only use the charger function and not manually switch between charge and power supply functions when needed. That's off topic but just in case someone wanted to mention it ;)

I'm more concerned about the longevity of the charger if it's supplying power 24/7 rather than simply charging the battery and then going into float.

I have also looked at more permanent solutions made for my exact problem (for ex. the multiplus range), but that's not an option right now as I'm in a rental place where I cannot make any permanent modifications, not to mention that it's way outside my budget :)

I also thought of the situation where once the power gets back on that some power from the charger will go into the battery and some to my devices, meaning the battery is not being charged as fast as it might have been. That's also a different problem.

I noticed it gets quite hot during the bulk stage, but I have a fan moving some air over it to help cool it down for what it's worth.

So is it okay for this charger to be spending a lot of time in high-current stages (will most likely spend majority of time in the float stage with about 5-10A current)?

wscholtz asked
wscholtz commented ·

1 Answer

Any way to program relay 2 to disconnect load after some SOC value?

Hi guys,

I have programmed a system with 2 Quattros of 10kW to obtain a 120/240 split phase system, also 1 Cerbo GX and 4 MPPT 100-250 controllers, and 20 kWp on PV power, and 30 kWh on storage by pylontech, an 20kW on propane generator.

The issue is that in relay 1 I have connected the start/stop functions of the propane generator.

Additionally, and the reason for the question is that the generator could not start due to various faults, such as an empty propane tank or the starting battery does not work or someone forgot to put the system in automatic mode,

so, as an additional method, it is required that when a low SOC level (something like 30 - 40%), relay 2 be programmed to disconnect the load and only leave the essential load running (like a refrigerator and a modem).

I understand that I require a contactor previously wiring to separate the loads.

thanks for your time guys,

Greetings from Baja California Sur, Mexico.


iruizh asked
wkirby commented ·

2 Answers

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