Quattro-II: V2L as AC-2 input

Q&A and troubleshooting EVCS
1

Hello everyone,
I have a Quattro-II 5k. I’m trying to use the V2L (Vehicle-to-load) from my electric car (Hyundai Ioniq 5) as the AC-2 input. V2L is a technology where an inverter is built into the electric vehicle, converting the high-voltage battery voltage into 220/110V AC. My car has an inverter with a maximum power of 3.6kW (230V, 16A).

Everything works - the Quattro outputs voltage and charges the battery. However, I’m concerned about the auto-oscillations (see and hear video) that occur when the Quattro operates from the car via the AC-2 input. These oscillations happen during the battery charging. It’s as if the Quattro-II charger cannot synchronize its operation with the electric vehicle’s inverter.

What can I do to fix this? Maybe try an isolation transformer?
I’ve tried using VEConfigure to increase/decrease the inverter voltage of the Quattro-II, enabled the Weak AC-input setting, and tried turning PowerAssist on/off. Nothing helps, the Quattro-II still hums unpleasantly and V2L power values jumping.

2

What is your input current limit?
Are you using ESS?

Check weak AC and remove LOM detection (if using ESS) that should help.

3

I tested a few AC-2 input limits: 3A, 6A, 10A, 13A, and 16A. The higher the limit, the louder the humming noise. I can’t go higher than 16A because that’s the V2L maximum. I’m using ESS Assistant. I’ll try turning off LOM detection. However, it seems like the AC-2 isn’t fully turning off but rather cyclically adjusting the battery charger power. It’s as if the V2L inverter and Victron charger are having trouble coordinating.

4

It sounds like there are current transients in the transformer, inducing resonance in the windings.

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5

Agreed.
It sounds like a modified wine wave or a very large harmonic content. Interaction with the quattro transformer. Speculation would need an o scope to tell.
So the behaviour of the victron system can be changed this can be tested with LOM and try weak AC as well.

I have never used it so i cant say for definite. But i have heard a sound similar and that how it was changed.

6

You’re awesome!

Disabling LOM and enabling Weak AC resolved the issue!

Disabling LOM alone wasn’t sufficient.

Now I need to determine if leaving Weak AC enabled is a reasonable long-term solution. Or perhaps I should create a separate configuration (with Weak AC enabled) for the infrequent V2L charging scenarios.

7

Fantastic.
Yeha weak ac changes the power factor. It’s really up to you there as the system admin.

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8

I pay only for active energy. So power factor doesn’t affect me. But V2L is very rare also)

9

I’ve been trying to figure out how the Weak AC setting works in my Quattro-II inverter. I’ve been charging my Victron batteries through the regular AC input (not from a generator or my car) with Weak AC on and off, and then checking the power readings on my smart meter. But I haven’t seen much of a difference.

Test conditions:
AC-1 input limit 32A (LOM is active for AC-1)
Batteries charging current limit: 50A (2.5 kW)
Both tests shows close to 44A charging current (Charge Current Limit for 90% SOC (3x Pylontech US3000C) at that moment is 44A), about 3 kW total inverter consumption and 0.3 kVAr reactive power. My house base load is approximately 300-400W.

So, I’m wondering if the Weak AC setting only affects the AC-2 input on the Quattro-II?

10

hello @FooBar
very interested in your setting with v2l, can you tell me if you managed to stabilize up to 3.7kW and if so how long max.
Thanks for sharing

11

All i have seen is that the max charge amps aren’t reached. But then we do have weak ac, so the system basically the function loads the connection as much as it can without making it unstable or dropping voltage.

A Post here

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12

Hello!
I haven’t pushed the V2L to its 16A limit for very long. I’m not sure it’s built for that kind of constant load. Charging the Victron battery takes hours, so it needs a steady draw of power. The V2L inverter might be up for it, but I’d rather play it safe, especially since I’m not in a hurry. So I’ve capped the current at 10A for the AC-2 input

13

Thanks for your feedback, I understand and you are certainly right, it is indeed wiser.
With 10A you were able to test for how many hours max
Do you have PV on AC or only MPPT?

14

The V2L inverter in my EV model is part of a complex component called the Integrated Charging Control Unit (ICCU). This unit encompasses the EV battery charger, a DC-DC converter (for 12V auxiliary power), the V2L inverter, and possibly other components. If one part fails, the entire ICCU may need to be replaced. Therefore, I’m hesitant to push the V2L to its limits and risk damaging this critical component.

15

No PV. Only Quattro and Pylontec batteries.
Thus far, I haven’t needed to utilize the V2L to power my Victron system for more than an hour. The main grid has been reliable enough to maintain sufficient energy reserves in the Pylontech batteries. However, I did use the V2L to power my home directly (connecting it to the generator input in my electrical panel) before purchasing the Victron system. During this time, the V2L operated for up to 10 hours. It’s important to note that this was for typical household loads (not battery charging) - a background load of 300-400W with occasional spikes of 2-3 kW when appliances like kettles, hairdryers, washing machines, and water pumps were turned on (not simultaneously, of course).

16

ah ok that’s great 10h is already not bad, I imagined doing it at night so we are on the same duration.
I asked you the question about possible PV in AC because I read that the V2L does not support having competition in AC and that it cuts if AC comes from somewhere other than it

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17

Therefore, we can assume that the Weak AC setting does not necessarily engage a less efficient mode but rather provides the option to utilize it when required. Consequently, if the source is of sufficient quality, performance can be as efficient as with the Weak AC setting disabled?

18

I haven’t analysed it that closely but I haven’t seen anything negative or noticeable when left checked on all systems, except different charge currents and how it ramps up.
Maybe others will have noticed with ac charge sources that have a different power factor or are more stable that what we experience here.

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19

This wasn’t the end of the story) Today I conducted more experiments. I charged the Pylontech from the mains with the Weak AC setting enabled and disabled. As a result, the power factor was 1.0 in both cases! This is good news!

Next, I decided to double-check that the Victron works normally from V2L via the AC-2 input.

To my surprise, it turned out that the Victron accepted the V2L, supplied power to the house, but did not want to charge the Pylontech, although yesterday it definitely did.

It tries to charge, but for some reason stops doing so. The consumption from V2L increases for a short period to, say, 10A and then after a short oscillation with vibration of the transformer windings immediately drops to a minimum (to the consumption of the load at the AC-1 output), while the VRM displays the Passthru operation mode for a while. Then the cycle repeats - again an attempt to start charging and again cancellation.

This is all with LOM disabled and Weak AC enabled.

I was confused and started thinking about mysticism)) I tried to disable Weak AC - but here without surprises, it works, but the oscillation and hum of the transformer are like in the video above, although not as intense - apparently disabling LOM helped partially.

In general, I tried different options, I clearly saw yesterday how it worked.

In the end, I was able to succeed. It turned out that yesterday I was just lucky, but it was a special case. So, the recipe is to start in NoLOM + Weak AC mode with a limit of 6A at the AC-2 input and then raise it to 10A. In this case, the V2L gives about 2 kW, 0.6-0.7 kW (at the time of the experiment) goes to the house, and ~1.2 kW for charging the Pylontech. When trying to raise the limit to 13A, a short oscillation and vibration of the windings occur (not immediately, after a couple of seconds), after which charging stops, the V2L consumption drops to the level of the house load (AC-1 output). Then attempts to start charging are cyclically repeated, as described above. That’s how it is.

It turns out that stable operation can only be obtained without Weak AC. Yes, it vibrates, the V2L consumption jumps (from 2.1 to 2.5 for example), but it works. Everything is great, it remains only to understand - how harmful are such vibrations…

Well, the Weak AC mode turns out to be ambiguous. On the one hand, 10A seems to be enough for me (even if you start with 6A), but on the other hand - judging by how it behaves, there is no guarantee that at some point, even at 10A, there will be a loss of coordination between V2L and Victron charging, after which the Pylontech charge will stop.

So far, that’s it. I want to try LOM + Weak AC, maybe it will be better…

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20

Maybe try reset to factory default and reset up.
Sometimes fiddling alot causes weirdness.
13A will probably be too close the V2L limit.
Often 80% of limit on a source is a good rule of thumb even if it is a stable source.

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