Voltronic Axpert VM 4 clone exceeds 2A utility charging current by over 115A

[anti77]

Option 02 utility+solar charging current max is set to 120A
Option 11 utility charging current max is set to 2A
As soon as I set option 16 charge source prio from CSO to SNU current starts increasing to 117A(124 measured) and stays there while fans spin at max.

This is a new inverter, seller does not have a clue. It is good that battery supports 250a charging current, but my mains will not if the load increases.

Inverter specs mention maximum 100A utility charging current, which is now exceeded. In CSO mode it does not charge with utility during the night where there is no sun.

Does anyone encountered similar situation? Is there a known bug in firmware? Does not seems to be hardware related, because if I change option 02 to a lower setting, the charging current does drop accordingly. It is just that option 11 is completely ignored.

 

[wattmatters]

That is weird and sounds like a (bad) firmware bug. Being a clone does not help on that front as firmware updates are a risky proposition, if they are available at all.

I'm assuming you don't have enough solar PV to generate that sort of charge current and it's almost all coming from the utility input.

All I can suggest is to validate that the setting of max utility charge current is actually being accepted. What happens if you select say 10 A rather than 2 A?

If it is not working as it should then I think you need to get it replaced with a unit which does operate correctly, or a return/refund.

Not that I have the same inverter but my two quite different AIO inverters definitely have a controllable utility charge current setting and it works as expected.

 

[anti77]

That was my first test, changed to 10A utility charging. That setting 11 (Maximum utility charging current) is completely ignored.

And no, solar string on 200V 0.2A was like ~1.5A charge to the batteries. Considering that there was a load, I assume that solar went to the load.

Otherwise it is a really good inverter, much better on MPPT than a Voltronic Axpert VM II clone I had before on the same panels. This one starts charging at 8:00 in the morning while the old one started only at 10:30. And no, the sun did not got more powerful in 5 days

I've read somewhere that there is a firmware bug on some of these clones, someone had their battery destroyed by over current, just that i can't find it now.

 

[anti77]

This inverter is branded ANERN, that is important as they have no clue what they are selling. Their "solution" was to set option 02 (maximum charging current to the battery) to 20A:



so they don't know the difference between the 15A-20A current coming into the MPPT module at around 160V-200V from the solar panel string that gets converted to around 100A-120A at 27V when charging the battery.


and they don't agree with what is in the manual, that setting option 16 to SNU (solar and utility - default) - " Solar energy and utility will charge battery at the same time".

Another issue with the same inverter is that the WIFI module stops working when the solar power gets above 1700w (COM led off), it automatically resumes when there is shade or the sun goes down.

My recommendation thus is to avoid this brand.

This was bought through aliexpress, opened a dispute, strangely I got a 30% partial refund very fast. Another strange fact is that for this order I don't have the invoice in my account as for any other order.

 

[anti77]

Third issue, at night, when there is like 1W input power from the solar string (e.g. street light), the LCD displays 0.100kW solar input. The app shows it correctly.

If I stop the PV string from the breaker, solar goes to 0, and it starts charging the battery with the current set at option 11...

 

[meetyg]

I think the problem is understanding SNU vs CSO.
SNU means Solar AND Utility (combined). So I think what you are measuring is actually mostly solar, and a bit of Utility.
Check with your clamp meter on the AC in side of the inverter, see how much it actually pulls from AC.