Quattro-II: V2L as AC-2 input

Q&A and troubleshooting EVCS
21

Another update!

I’m probably annoying you all by now, and I’m definitely driving myself crazy! But I want to figure this out as much as possible and document it so others can benefit from the information…

So, after the experiments described above, I went out for a couple of hours. I left the system in noLOM+WeakAC mode, and everything was working as described in the previous post. Before leaving, I lowered the ESS minimum SOC to 85% to discharge the battery (increasing the CCL), thinking it might somehow influence the issue.

When I returned, I connected the load again, starting with 10A, and… it worked! Immediately, without any oscillations or vibrations, I could hear the charging power increasing smoothly and the transformer humming steadily. I was shocked! I increased the load to 13A - it worked. Then to 16A - still working. I cycled the power multiple times - it worked flawlessly, smoothly, and without any oscillations!

What was that? Did it need a lower SOC? Maybe, although I don’t understand how that could be related. I’ll charge it back up to 90% now (as it was at the beginning of the experiment, I usually keep the SOC around 90%) and see if it still works.

There’s another theory, but it seems rather unrealistic from an engineering standpoint. Nevertheless… All my experiments were conducted shortly after uploading the Remote config via VRM. Is it possible that even though we receive a message confirming successful configuration upload, the Cerbo actually needs some time to “process everything” and configure the Quattro properly?

A few moments later…

Okay, so I charged the Pylontech to 95% and… it works! I don’t understand what’s happening. There were no oscillations… However, a couple of minutes later, my wife turned on the 2kW oven, which, together with the other loads, exceeded the 13A limit. The VRM started going crazy - switching between External Control, Passthru, and External Control again… At some point, I noticed slight oscillations and vibrations… Plus, I caught a situation where the AC-2 limit was 3A, but the inverter was in Passthru mode, loading the V2L with 2.8kW, while the Pylontech was in Idle mode… I have no idea what’s going on… I need to read more about ESS and Passthru…

Actually, I don’t really understand why I configured ESS in the first place. For a couple of years before that, everything worked perfectly “out of the box,” without ESS and any hidden or obscure logic present in the ESS.

In conclusion, I give up! We can conclude that in a prolonged off-grid situation, I can apparently charge the Pylontech from the V2L. That’s probably enough )

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22

I’ve been thinking about removing the ESS from my system. I’m still unsure about its value, particularly given the infrequent power outages in my region. The primary benefit seems to be maintaining a lower SOC, but I’m not convinced it’s worth it. Do you have any thoughts?

23

If you don’t really mix grid and solar with your system then yes, remove ESS.
Unless you are discharging during peak and charging in lower tariffs?

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24

Here is another brave guy who has 2 quattro and the V2L of his Kia
:grinning:

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25

So, I removed the ESS and retested everything, then reloaded the backup with the ESS to compare. Then I removed the ESS again (loaded the backup without the ESS). Had some fun ))))

Regarding V2L operation, it’s better without the ESS. Not perfect, but definitely better. Here too, I had to enable Weak AC; without it, there was an oscillation in power consumption from the V2L and an audible vibration of the transformer windings inside the Quattro-II.

It’s worth noting something else, which is really important for everyone!
Above, I wrote that I tested charging from the mains with Weak AC enabled and disabled. In both cases, the power factor was 1.0.
This was a test conducted with the ESS installed.

After removing the ESS, I conducted the same comparative test, and here the results are different. When charging the Pylontech from the mains with Weak AC enabled, the power factor is 0.82-0.83, and the Pylontech charge current is limited to 42A of 70A max available for Quattro-II 5k

It would be great to have a quick toggle for Weak AC or the ability to enable it only for AC-2.

26

What firmware are you using though?

27

Latest
v3.50 for Cerbo
v552 Quattro-II

28

I was looking into utilizing V2L with my residential installation - Victron Quattro+pylontech batteries operating in ESS.

But I wasn’t so keen on using the spare generator AC input of the Quattro, as I can’t remain grid connected or export to grid.

An alternative solution seems to be to convert the V2L back to DC (e.g. using a Multiplus set to say 10A max) and then connect into the DC busbar.

Some automation in Node-RED would allow you to manage where the power goes e.g. cover the loads but not charge the pylontechs, with them then being used for any larger loads.

I can understand there would be some additional conversion losses using this approach, but the advantage is ESS remains grid connected (like a V2G solution) and it should avoid any of the above issues.

Any thoughts on such an implementation?

29

As far as I know when AC2in in use AC1in is complete disconnected from grid, so there are no chance to export anything…
AC2in is a fallback option when AC1in power supply is absent. AFAIK out of the box (no any Node-RED tricks) there are no way to make AC2in active together with AC1in.

30

Yes, that’s right. Those two are not in phase of course. My point above was connect to EV V2L via DC/battery side using a charger, then grid remains connected.

31

I got your point. But what for? As a backup option?

32

An implementation of V2H. Also with different import and export tarrifs the ability to export from EV without cycling home battery (V2G- like). Backup is already there with home battery, but is of course extended with this.

33

Hi ,
I will be trying exactly similar consition in January ( waiting for my BYS seal). I have a 8kwx 3 phase ESS with BYD 24 Kwh - Since my generator of 5 KW is single phase I use my Old quattro 5 KW to charge the battery through lynx bus ( ye slots of losses but much cheaper than running a 30 KVA 3 phase gen for nighttime loads) the quattro disbale charging using GEN start /stop command from Venus GX

Since my BY D seal ( 2025) has 6 KW onboard inverter I am thinking of using the AC1 input of 5 KW quattro ( simulated grid) since there is nothing on secondary of 5 KQ Quattro it should nicely charge the main abttery at 3.5/3.8 KW ( 70 amps DC limit of quattro)
Hopefully this will keep teh CAR and inverter happy
I will post my expereince once everything is up and running

p.s. ( only if Victron could make a V2H EVCS - Australia will start V2H from JAN 2025
Australia V2H in 2025

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