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Grid overvoltage causing issues with batteries ESS

I have a Multi II 48/10KVA 230V with a Fronius Primo (AC Coupled) and MPPTs connect to Pylontech US3000C batteries x 10.

The residencial area has a lot of solar and occasionally, the voltage on the grid gets to 253 which is the discconect limit on the Spain grid code so correct functionality. That is, at 253V, it disconnects from the grid.

The problem is this generally occurs when the batteries are fully charged and exporting excess power. Disconnecting causes the excess power to go to the batteries which are already fully charged and causing a battery overvoltage alarm.

It appears that the problem is caused because of the time it takes to ramp down the Fronius Primo and the 2 x MPPTs.

My feeling is that this is going to become an issue in many areas as solar grows and the grid is forced to up their voltages due to feed in.

I am thinking of changing grid code to one which accepts a higher overvoltage setting (UK for example) but wanted to know if anyone else has solved such issues and how it is solved. Suggestions welcome.

ponzoa asked
Alexandra commented ·

0 Answers

Why would 2 x 24V panels in series read 80+V PV?

Hi everyone. I have Victron solar panels; each is 24V rated 200W, they have 72 cells instead of the normal 60, and I have four pairs of them. Each pair is in series to give 48V nominal and each pair has its own MPPT. When I read PV from the MPPTs the starboard side shows 60V on one pair and 65V on the other. This is a little high I think but the port side reads over 80V on both, which is concerning. Does anyone know why this might be happening and how concerned I should be?? Thanks in advance.

eyacht asked
groningen edited ·

5 Answers

Batteries high voltage error

Dear all,

I installed an island, 3-phase system with 3 multiplus 2 48/3000, a 3-phase SMA 10.0 Tripower PV inverter and 2 pylontech us5000 batteries.

When the batteries load, the system works like a charm, but when they get to 100% there is always a full shutdown due to high voltage errors. I set all the charging voltages in several menus (victron connect and directly in the cerbo gx) to 50 V, so it should stop charging, but it always runs up to 54 V and then produces the error.

My suspicion is, that the frequency shifting for the inverter does not work as intended.

Any help is greatly appreciated.



Sebastian Jaksch asked
michaelvh answered ·

4 Answers

High Voltage Alerts - newbie questions - (setup details provided)

My first post. A newbie to Victron Systems. Installation is in a professional campervan conversion that is less than one year old. Built for boon-docking for several days at at time.

Renogy PV panels - 600 watts total
Pylontech LiFePo4 100aH batteries x 4
Victron Cerbo GX firmware - v2.89
Victron Orion Smart 12V/12V-30A firmware v1.13
Victron SmartSolar MPPT 100/50 firmware v1.61
Victron MultiPlus 12V 3000 120-50 120V firmware ?
DVCC screens below

AC loads are 1800W induction cooktop, 450W milk frother, chargers for laptop/tablet/portable

High Voltage Alerts (HVAs) frequent after batteries reinstalled from wither storage. Assuming that was the batteries balancing themselves? See HVAs again because of small AC drain and high solar input. (3 days off grid and batteries did not drop below 86%).

So... questions
1. Will I be always chasing HVAs because DC-DC charging + PV charging capabilities
may often outstrip AC loads?

2. Will continuing HVAs cause battery damage over the long haul?

3. Are their setting changes that will dump/divert excess charge?

4. Any other basics here that I am missing?

Any guidance greatly appreciated.



jswyukon asked
mvas edited ·

1 Answer

DVCC: "Max Charge Voltage" not considered when ESS in "keep batteries charged" mode?

Dear all,

I'm using ESS on a Multiplus 2. I've gone already to related posts in:

and I've configured the system according to: https://www.victronenergy.com/live/battery_compatibility:pylontech_phantom

My Problem:

When I operate ESS in "keep batteries charged" mode, I get "High DC ripple" Alarms and "High Voltage" Alarms leading to shut down the Multiplus at high solar yields (as already described in other posts), even though I've set the "Max Charge Voltage" in DVCC to 51,7 or even less.
Observing the local terminal, I can see charging current although the battery voltage is above 51,7.

When I operate ESS in "Optimized with Battery life" mode, I don’t get Alarms nor shut downs. At the local terminal I can see even discharge currents in case the battery voltage exceeded the limit set in DVCC (after changing from "keep batteries charged" to "Optimized with Battery life" mode).

From what I've seen it appears to me DVCC limits are being not obeyed when operating ESS in "keep batteries charged" mode?

Anyone having similar problems respectively is there any solution to stable- and reliably run ESS in "keep batteries charged" mode ?

BR Andreas

My HW configuration is:

  • Multiplus-II 48/3000/35-32
  • Venus GX Firmware: v2.73
  • 4 x Pylontech US2000C Firmware: v2.7
  • SMA SunnyBoy on AC-Out 1

andreas-0676 asked
alberto-fernandez edited ·

3 Answers

Victron MPPT 100/50: Doesn't go into Float...

I have the Victron MPPT 100/50. It's a 12 volt system hooked up to solar panels and eight 6 volt batteries. I'm inputting over 600 watts from the panels. The battery section of my SmartSolar app I use on my iPhone says my voltage is over 14 volts but I still see that it's in the Bulk mode. I'm concerned that too many charging volts are going into the batteries because the Victron hasn't switched to Float mode. Does it take awhile to go into Float? Here's what I have in my settings:

Battery Voltage: 12V

Max Charge Current: 50A

Charger enabled: Yes (on)

Battery Preset: User Defined

Absorption Voltage: 14.40V

Float Voltage: 13.50V

Equalization Voltage: 16.20V

Automatic Equalization: Disabled

If I see a voltage of like 14.5 and it's still in Bulk mode, can that be dangerous? Thanks!

ajbremer asked
kevgermany edited ·

1 Answer

suppress "high cell voltage alarm" from BMS (


is there any option to suppress the "high cell voltage alarm" display in the remote conlole of the VenusOS (v2.94)? (I dont need this alarm, cause the BMS Overvoltage is set very low (to 3.47V) to force the very unexact SOC of the BMS to reset to 100% so it will drift away less. But the high voltage alarms are annoying.

MP2, JK-BMS; with serialbattery driver

Thank You


berndm asked
berndm edited ·

1 Answer

ERROR: Max Charge Voltage (52.4V, Pylontech) ignored, when limit Grid feed-in in ESS settings

Hello, there is a bug in the system. My Setup:

3xMP-II 3000, 3xPylontech 5000, 1xMPPT RS 450/100

Victron stops charching above 52,4V with Pylontech batteries. This works perfect until i limit the Grid feed-in in the ESS settings. AC and DC feed-in is activated.

AC inverters (Kostal an Hoymiles) are connected to the AC out1 of the MP-II and are not regulated with the GX-system.

I've got an Overvoltage error from the Pylontechs: 56,7V !!!

Is there a solution for this?


parateam asked
parateam answered ·

2 Answers

SmartSolar MPPT 100/15 raising battery voltage too high

Hi everyone.

I'm currently using a MPPT 100/15 with a 12V battery bank (2 x 12V 100Ah Lead Acid batteries in parallel) with 2x100W solar panels. The solar controller's settings are on 14.4V absorption and 13.9V float. The equalization voltage was set to 16.2V but it is disabled and I've never manually triggered the equalization.

I also have a BlueSmart 12/15 charger which I set on power supply mode during the day with a voltage of 13.4V while the solar panels provide power to my system. It's charge mode's settings are similar to the solar charge controller (14.4V absorption, 13.8V float and 13.4V storage).

Earlier today I noticed a strange series of events.

1. The power from my solar panels dropped from around 130W to zero. (it's a sunny day, panels had no shade, I measured the panel voltages and everything seemed fine on the panels and at the cable going into the solar charge controller when unplugged - around 70-80V open circuit voltage). After this the Victron app stated that the charging state is "Off".
2. The reported voltage on the victron connect app showed that the voltage from my solar panels dropped from the normal 65-ish Volts to just above the battery voltage. This was thus different to what I measured with my multimeter at the cables going into the charge controller while they were unplugged.
3. I changed the BlueSmart charger from power supply mode to charger mode, detached the solar panels and measured their voltage (mentioned in point 1).
4. I re-attached the solar panels.
5. Soon thereafter I heard a boiling sound coming from the batteries and noticed the battery voltage going over 15V and steadily climbing.
6. I immediately switched off the BlueSmart charger, but it had no effect.
7. I then detached the solar panels which brought the voltage down again.
8. To investigate I tested this by leaving the BlueSmart charger switched off, and re-attached the solar panels. The voltage started climbing again.

Afterwards I took some screenshots (below). It's quite clear on the screenshots that the voltage climbed each time I re-attached the solar panels.

What I'm seeing is:

- The solar charge controller is in an "off" state.
- The charging current was showing zero
- The power and current from the solar panels were showing zero
- The battery voltage kept on climbing and I heard the Lead Acid batteries boiling.
- Even though an audible boiling sound came from the batteries, the solar power and current and battery charge current all showed zero.

What am I missing?

It almost seem like the battery voltage was chasing the solar voltage. I don't think this was an equalization happening because during "step 7" I did decrease the equalization voltage to 14.5V and the battery voltage still climbed past it to 16V+ before I detached the panels again.

Did my SmartSolar MPPT charge controller break? It's only a few months old now.
Did it perhaps somehow decide the batteries are 24? I double checked the settings and the battery is set to 12V. At no point in time was the battery cables disconnected.

I will be testing everything again in the morning when the sun is back up and if anything changes I will comment on this post.



wscholtz asked
wscholtz commented ·

1 Answer

Unstable Grid: how to keep connected but without disrupting the EasySolar II?

I've look at some posts like:



But I'm not sure if my problem is like the ones above.

The problem: Now, everytime I connect to the grid, in a few minutes it will turn off my tiny-house electricity. And then it may come up later.

I'm connected to a poor grid, long cable.

I don't have VEConfigure so I can't e.g. disable LOM or anything like that.

All I wanted is: be connected to the grid, even if it's poor (I try to set limits to import or export to the grid), and when the grid fails, I want the victron to keep running my electricity from the PV or battery like if nothing had happened, but no, it's disrupting, shutting down everything. It should just disarm the relay and not shutdown my house.

alans asked
klim8skeptic commented ·

3 Answers

Voltage limit on MPPT

Hi Folks,

I'm looking to understand the MPPT max voltage limit a bit more, for example the 250/100 MPPT.

Max voltage being 250v. Say I have panels with VoC of 49.5, and put 5 in series. (Awfully close to 250v)

VoC is technically under 250v however in practice, in the scenario cloud -> sun with battery disconnected for whatever reason I suspect 250v would be breached even if for a short period of time.

Is the 250v limit on MPPT based on VoC (ie likely has a buffer for the niche scenario described above), or is 250v a hard limit and installers/system designer should add a buffer themselves to ensure the 250v is never breached or is VoC * number in string sufficient.


matt1309 asked
matt1309 commented ·

1 Answer

Multi 2 Overvoltage on Float


My system has developed a problem that I hope someone can provide a solution. I have Multi 2/5k/48v system with 3x genz 3kw modules (174ah). Just recently when the float voltage is reached (55.4vdc) it keeps rising (if I let it) to 62vdc when the Multi will switch off (or the battery BMS switches off??) I normally go and switch the solar off which causes the system to invert. (The GENZ LIFEPO batteries are designed as a drop in replacement for AGM etc and has no external BMS only its built in management)

The system has been fine up until recently. I tried updating CCGX and multi but to no avail. The BMV is set as recommended - Abs = 57.6, Float = 55.4.

System: Multiplus 2 5000 48vdc (An early model, Colour CCGX, VE Bus Smart Dongle and Enphase S270 (3kw) Solar on AC1 Out.

Has anybody come across this before?

Cheers - Paul

bassman asked
bassman commented ·

1 Answer

Charger IP67 12/25's going nuts: voltage fluctuates in Bulk, Abs, Float, Storage


any help is appreciated. IP67 12/25 is connected to AGM battery with 92 Ah, temperature -2° C.

In all charging states the volate is fluctuating. Charge algorithm "AGM spiral cell" has been chosen (abs 14,70V, float 13,80V, storage 13,20V.)

On the left you can see the charger working in storage-mode. DC-load was 3W for Globallink 520 and some USB-sockets without any load. Look at the curve: Voltage is fluctuating every second (not seen here because Globallink gathers data only four times an hour.) But when i am checking the Voltage via Bluetooth right beside the installation i can see that voltage fluctates between min 13,30V and max 13,70V! That i am not reaching 13,20V is ok due the temperature of the battery while using temperature compensation as it is set by factory (-16,70V/°C) Is that normal behaviour?

On the right side of the chart you can see the same battery being charged without any load by a CTEK MX 5.0 Polar. This charger also compensates the batteries low temperature but look at the voltage of the charging states: bulk, abs and float are clearly visible and NO VOLTAGE HOPPING.


thshh asked
thshh commented ·

1 Answer

High voltage alarm setting

After a year of use our system has recently started raising high voltage alarms and I am wondering if I have a problem as I am not aware of anything having changed in the setup.

The setup is:

* Bank of 2 Victron AGM 100A connected to a Victron 100/30 MPPT and monitored by a BMV 702 which also monitors battery tempreature

* Bank of 2 Upower AGM 110A connectyed to a Victron 100/50 MPPT not currently monitored as I am replacing the NASA marine BM1 monitor with a BMV 702 and have not completed the installation because of difficulty of access.

* Shore power charging via a Sterling procharge 40A which is connected to each battery separately (supports up to 3 banks).

* Victron Cyrix-ct VSR is used to share charge between the battery banks when shore power is not switched on and a circuit breaker is used to isolate the battery banks when shore power is on.

The system is in our boat which is currently hooked up to shore power. The problem started a few weeks ago: when shore power was disconnected and then reconnected the voltage whould spike and take a while to come down. We switched of the mains charger as we could manage on solar but we are still getting an alarm when the sun is sufficiently strong to initiate charging, thougth the alarm is at a lower voltage and clears more quickly.

I am not getting any low voltage alarms on the battery so I don't think they are getting discharged to a low level, and when we were getting alarms with the mains charger connected the batteries were pretty much full.

The mains charger and MPPTs are set at the default settings for AGM batteries.

The BMV has the high voltage alarm threshold set at 14.7 and clearing at 14.5. I am contemplating setting the threshold to the fast charge voltage of 14.9.

The only thing that I can think of as being different is that the water temperature may be lower (about 11 degrees C) than when we commissioned the system.

roberts asked
roberts answered ·

3 Answers

Setting DVCC volts for LFP 16 cells battery

I have LFP 100Ah 16 cells from "XD battery" and MultiPlus 48/5000. Both connected via Cerbo GX, via VE.Can configured as BMS Can. Related configuration already done in VE Configure.

XD Battery datasheet (got it from the vendor).

I always getting over-voltage error, as on Cerbo GX, as on battery BMS.

I started from 56V and went to 54.9V charging voltage. The last one is not enough to have 100%.

Whole process diagram:


At the point (1:12) where lowest voltage goes down, the inverter stopped charging.



Is there something wrong with BMS or/and VEConfig settings, or anything else?

Why highest voltage raises and lowest goes down after stop charging?

kirby asked
snoobler commented ·

1 Answer

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