I would like to share a real case with a Victron ESS system that has been operating normally for several months and started showing abnormal behavior after a lightning strike nearby. I’m looking for insights from others who may have experienced something similar.
System description
3 × Victron Quattro 48/10000 (120 V version)
Configured as a three-phase system (one inverter per phase)
3 × SmartSolar MPPT 250/100, each connected to:
9 × Trina Solar Vertex II 505 Wp
Configuration: 3S3P per MPPT
Total PV power: 13.6 kWp
Battery bank:
4 × Pytes V5° lithium batteries
51.2 V / 100 Ah each
Connected in parallel → 51.2 V / 400 Ah
GX device: Cerbo GX
Location: Calderón, Quito – Ecuador
System type: ESS with grid connection
Loads
The system supplies:
Industrial loads (motors and crane)
Server and IT equipment
Office loads
I am intentionally omitting details about motor control / VFDs, as I want to focus on the ESS, grid interaction, and battery behavior.
Issue description
The system worked normally until about one month ago, when a lightning strike hit one of the buildings on the site (not a direct strike to the PV array or inverters).
Since then, the system shows the following behavior:
The system sometimes connects to the grid normally and can stay connected for several hours
After some time, it disconnects from the grid without any utility outage
The Quattros attempt to reconnect, but the system bounces back to battery mode
The grid is present and stable when measured externally
The “MAINS ON” LED turns off even though grid voltage is still available.
Relevant GX / BMS messages
When higher loads are present, the Cerbo GX reports:
Pytes Battery: High discharge current
Pytes Battery: Internal fault
After these events, the system may remain unstable for some time before reconnecting again.
Additional observations
No persistent VE.Bus error is shown
Grid voltage and frequency appear to be within normal range
The system behavior is intermittent, not a permanent failure
Ethernet on the Cerbo GX no longer works (possible lightning damage), but GX monitoring itself is stable via local access or WiFi
Questions for the community
Has anyone experienced grid connection instability after a lightning event without obvious inverter failure?
Can BMS protection events (high discharge current / internal fault) cause the ESS to drop grid connection and reattempt synchronization?
Are there known cases where a single battery module or BMS issue destabilizes the whole VE.Bus system intermittently?
Any recommended diagnostic steps to clearly differentiate:
grid quality / AC-in issues
internal Quattro damage (transfer relay, sensing)
battery or BMS-related protection events
Any insight, similar cases, or recommended tests would be greatly appreciated.
Thank you in advance for your support.
Best regards, Juan F. Vásquez
PV / ESS System Integrator – Ecuador
As the Cerbo has a fault on the Ethernet port, I would start by replacing that. There may be other damage that is not immediately apparent, but still causing glitches.
I would also place the system on standby, and see what the IP protection logs of the inverters are showing, after a period where the system disconnects from the grid. (you will need a Mk3 adapter and laptop for this - VE configure software).
Also: Do check to see if all of your batteries are sharing current equally. an internal fault on one or more BMS cards may lead to that battery disconnecting from the bus, and cause high discharge fault on one or more remaining batteries. This may also impact ESS behavior.
Pretty much this.
Whilst you may not have had a direct strike the energy still gets in places you would think are unexpected.
The truth is we all share a connection through grid and so can be affected even if it is not that close. Then there is the emp from it and various other phenomenon caused by it.
Do you have any surge protections on the ac and dc side?
Basically if it was serious enough everything should be checked or changed somtimes incoming breakers have become faulty/high resistance which could contribute to the ac connection issue you are talking about.
As an aside. Sometimes just shutting down the whole system and waiting for a few minutes for everything to power down and dissipate capacitor banks and then a full restart can clear many issues.
Hi, We have read your post about your pytes battery with victron inverter and the problem you are facing, We want to ask you if your V5 batteries has wifi device? if yes, can you share the SN code on wifi device, we can help you check whether Pytes batteries are working normally.other option is if you can give us access to your VRM. we can let our technical team check battery side of system for you.
I don’t have a wifi device for the batteries. However, i can give you acces to my VRM. I would need an email for that. Or is there any other way to give you acces?
After extensive testing, the issue was not related to ESS configuration, DVCC, battery parameters, or the Quattro inverters themselves.
The root cause was a damaged Victron VM-3P75CT energy meter, which had been affected by a lightning strike and was still configured as the Grid Meter in the system.
Because of the damage, the meter was reporting incorrect and inconsistent grid voltage values per phase, which caused the Cerbo GX to:
misinterpret grid conditions,
see severe phase imbalance / out-of-range voltages,
repeatedly disconnect and reconnect AC-in,
resulting in the observed “grid bouncing” behavior.
This also explains why:
the system was stable when the Cerbo GX (VE.Bus) was disconnected,
the problem reappeared immediately when the Cerbo was reconnected,
and why changing ESS modes, DVCC behavior, or inverter parameters did not solve the issue.
Solution applied
The communication wiring to the VM-3P75CT was replaced for testing.
The meter was then removed / disabled as Grid Meter in the Cerbo GX configuration.
After removing the damaged meter from the system logic, the ESS immediately became stable, with normal grid connection behavior.
The system is now operating correctly.
Important takeaway
In systems with Cerbo GX and ESS:
A faulty or lightning-damaged energy meter configured as Grid Meter can silently destabilize the entire system without generating explicit meter alarms.
After lightning events, energy meters and CTs should always be considered potential failure points, even if inverters and batteries appear healthy.
Hopefully this helps others facing similar post-lightning or unexplained ESS grid connection issues.
Best regards,
Juan F. Vásquez
PV / ESS System Integrator - Ecuador.
I am intentionally omitting details about motor control / VFDs, as I want to focus on the ESS, grid interaction, and battery behavior.