Inverter not charging

Why would my inverter not be charging the batteries when it is on the generator? I have a Victron Quattro-II. The grid is on AC 2 and the generator on AC 1. The generator is an 8kVA one and its output is around 224V and naturally fluctuates a bit.

What should I be checking?

The charging issue is secondary. The inverter does not register the AC on either input 1 or 2 coming from the generator. Obviously it won’t charge the batteries if the is “no AC”.

However, when I connect to the console and go into the inverter, it shows “Active AC Input” as Disconnected, but AC-In L1 reads 225V. The frequency fluctuates quite a bit. Anywhere from 50Hz to 53.4Hz. Could this be it? Must the frequency be more stable before the inverter “accepts” it as grid power?

I think this is it. In the VE Configure app, I have the SA grid code selected and in its settings I the over freq. value is 52Hz.

So, my question is, with everything else left as is, can I change the grid code selection to “None” and use the default settings, i.e.

Accept wide input frequency range (45Hz-65Hz)
AC low disconnect: 180V, connect 187V
AC high disconnect: 270V, connect 265V

Note, I am not grid tied yet, so I have to manually switch over to the inverter/generator.

Yes. If you are not grid-tied, you are allowed to do that, and it may in fact be the only way to make it work.

As far as I know you can configure this per-input on the Quattro, so usually you’d put the generator on AC-in-1 and configure it rather promiscuously, and you’d put the grid on Ac-in-2 and configure it strictly according to the grid code.

(why generator on AC-in-1? Well, because that has priority. When two AC-inputs are both active, the Quattro selects the first one that is acceptable. By placing the generator on AC-in-1, simply starting the generator automatically uses it, without extra switching).

Thanks plonkster. It took a few tries, but the generator is charging the batteries now.

We had a cable theft, so I have been off for 14h so far. The generator should hopefully not be needed often.

I will play a bit when I have more time to dial everything in.

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I need some clarification on how a generator works in combination with solar panels.

I understand the way the system to be working as follows - bases on my observations over the past 2 weeks or so since my solar panels were installed:

My system is set to 80% DOD. So, when grid power is available, and the batteries have reached 20% SOC, the load is supplied by grid power and the batteries are charged up to 28% with the panels (assuming solar power is available) and not the grid. Once 28% SOC is reached, the load goes over to be powered by solar - (and supplemented by the batteries if the solar is insufficient). As the solar power increases with the sun rising or clouds clearing, the batteries continue to be charged and the load powered all via solar.

Now, suppose there is no grid power available, and the system has reached 20%, it will continue to discharge to 15% SOC - which is how the system is configured at present at which point the inverter switches off. At this point, when I start the generator and switch on the inverter again, what is supposed to happen?

Will the generator only power the load and not charge the batteries (i.e. same behavior as when there is grid power), or is it supposed to do both? Is there a setting that controls this?

Ideally, I want the generator to always charge the batteries when it is running so that I can get as much value of out of the burnt fuel as possible. No sense having a generator running to supply a few hundred watts every now and again.

Depends on the size of the generator and the load it needs to power.

I’ve read, if one can use a generator to charge the batteries only, that that is the most cost-effective way to use a liter of fuel.

Batteries will simply take ALL the power the generator can give (T&C’s ito the bank size) until that point where they need to be charged slower.

Inverter will take all the power the gennie can give, supply the house, what is left over, send towards the batts.

BUT … IF the gennie is too small for the loads at the time, the inverter will try and use the batt, see it is too low, and switch off again.

So it depends on the gennie size and the load demand.

You said you have a Quattro, which means it has two AC inputs. Normally you would put the generator on AC1, and the grid on AC2 (the other way around is also acceptable, but there are caveats I won’t get into), and then in Settings → System Setup, you will tell the system that there is a generator on the relevant input.

What happens then, is when that input comes alive, the system knows that the source is a generator, and it will charge the batteries. It will essentially switch to “keep batteries charged”. If your load on the output exceeds the AC input current limit (if you have one set), it will discharge the batteries to avoid exceeding that limit, but other than that… it will charge batteries to 100% or until you switch back to grid or turn the generator off.

Thanks for the replies so far.

I do have the generator on AC1 and I have the following settings:


I saw that I can set the current limit via the VRM portal - which is nice. :wink:



Do these look correct?

They look correct, but there is some issue with “weak ac input” that is presently escaping my memory. When used with ESS, there is a situation where it starts charging, then sees a frequency variation from the generator, pulls back… etc etc. Perhaps try without that and see if it works.

And make sure on the GX you have AC-1 set to generator.

Thanks, Izak, I’ll change the “Weak AC input” setting and see what happens. That might be what happened this morning.


So that is correct.

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