Setting the maximum grid load

Hi. I live in Queensland. I looking to purchase an EV charger and I am attracted to NZ designed and built technology. I have a 10kW solar system and single phase grid connection. Unlike other states, Qld has an irritating connection rule: An EV charger can only be connected to an uncontrolled tarrif if it is limited to 20A. An EV charger which draws 32A must be connected to a circuit on a controlled tariff. If I go down that path I will not be able to use my solar to charge my car. My question is: Can the E2 EV charger be configured by the technician to set the maxium grid current to 20Amp. If the sun is sufficiently shining (which it does quite a bit in Queensland), then would it be able to charge to the 7.2KW / 32 Amp capacity? Further, if the Government subsequently decides to change this rule, would I need to get the technician back out to reprogram the device?

Hi Gerard.

Good question! At this point the only limit which can be set is the output limit, so it does not take into account the fact that really it is the grid limit which matters for your purposes. However, a solution for your Queensland scenario is definitely on our near term roadmap, because as you say it is not useful if you have to connect your solar charger to the controlled tariff.

Regards,

Tom

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Hi Tom. I have not yet purchased a charger. In your response abovle back in September you indicated that a solution for the Qld grid limit was on your ‘near term roadmap’. I am wondering how close to ‘near term’ that is. Should I hold off purchasing a charger? Gerard

Hi Gerard.

It’s currently undergoing implementation, and will require a solid amount of testing; t’s part of a number of changes to the logic that determines how much power to allow in a range of scenarios, all of which affect each other and need to be reconciled! So I doubt the release will be this side of Christmas and will likely become available in January.

Of course, all our chargers are firmware updatable, so one option is to get it installed now with the output limited to 20A, and then raise the limit to 32A with a “from-grid-limit” of 20A once the logic handling that case has been loaded onto your charger.

Regards,

Tom

Thanks for the quick response Tom. I have been involved in software development, I can imagine there are many scearnios that need to be tested. Very exciting though to hear that this feature is coming soon. If I get it installed before the firmware update, will I need to get the technician to return and reconfigure?

No, we can push new firmware remotely (important if there were ever to be a fault that requires an update!). Usually this slowly happens across our fleet over a couple of weeks so that we can monitor that all is well as we go through it, but we could ensure your charger is one of the early ones given that there is a specific new feature that you want to activate.

Hi Tom. I have finally just put my order in for a E2 charger. I was wondering if the firmware update discussed above has been successfully developed, tested and deployed? I am looking forward to my new charger.

We are deep into field trials so it’s quite likely that it will be formally released by the time your charger gets installed, and if not I can easily update it for you manually.

Hi Tom,

I’ve got an X22 Evnex charger for the past 2-3 weeks. It is currently running firmware 2.2.1.6548CA5. I noticed from you website that v2.3.0 was released in Oct 2023, and includes “Changes to solar control to prevent home battery discharge”, which is important to me for a different reason.

I’m also wondering about the maximum grid load feature from this post and what version of firmware that will be released in?

How do I update the firmware on my Evnex charger?

Hi Rainer.

Firmware updates should roll out steadily across our system. I’m not sure why yours didn’t get updated but I have just updated it to firmware 2.5.0 which includes various solar control updates and has been approved for release - albeit not on the external facing website quite yet.

I’ve configured it for your setup including avoiding battery discharge. For the moment that won’t appear cleanly in the app (I recommend you just don’t open the solar diversion page), but it will now solar charge following the net export across all phases and will maintain a small export at all times to prevent your battery from being drained.

This is the version of firmware which enables setting a grid import limit too, but given you have a three phase charger I don’t think you are required to do this?

Kind regards.

Tom

Hi Tom

My Evnex charger was installed a couple of weeks ago. I am very pleased with it. It is working perfectly. It appears to be running on Firmware 2.4.1. I assume the Grid Import Limit needs to be set by you, or via the installers app. I think the installer may have overlooked the local rules about the 20A limit. However, if you are able to remotely set the grid import limit to 20A I think that my installation should be compliant. Is it possible to do this without any hardware changes? Obviously, you have a CT clamp which monitors what is going to the grid, but do you also monitor what is being produced by the solar (or what is being consumed by the other loads?)

Hi Gerard.

I’ve also updated yours to 2.5.0 and set the grid import to 20A.

No we only monitor what’s going to and from the grid, not the direct output of the panels.

Glad the charger is meeting your needs!

Kind regards,

Tom

Thank you Tom for upgrading my system to 2.5.0. I have been charging the car this afternoon, I have to admit the way it has been implemented was not what I was anticipating. It looks like the charger is drawing a maximum of 20amp - not drawing a max of 20 amp from the grid. It is currently charging at 4.5kW. However, I am generating some energy from solar - say 1.5kW. So I hoping the car would be charging at about 6.3kW (1500 + 20x240). I am guessing this is the only way this can work if you are just measuring grid current, and not solar generation as well.

Hmm. Not what I would expect either.

It looks like you are set to match solar all the time which means it should aim to have zero import or export - unless you activate Charge Now in which case it would allow up to 20A of import (I say up to because if you are generating lots then you may hit the overall 32A limit with less that 20A coming from the grid).

I’ll go through it with the hardware team in the morning to see what’s going on.

Tom

Yes, so this afternoon, I activated Charge Now, expecting it to import 20A and consume what ever the solar was producing - up to the 32A limit. You probably have access to it, but attached is a screenshot from the Session History, showing this afternoon’s session. Also attached is a screenshot from the inverter app showing load, export and solar generation this afternoon.


Screenshot 2024-05-08 232949

Hi Gerard.

Just confirming we’ve been looking at this to understand what’s going on as there are some differing interpretations between our team that we need to clarify. I’ll update you once we come to a conclusion!

Tom

… that does sound like software engineers! Just an update. This morning, I plugged my car in and activated ‘Charge Now’ later my solar started generating > 4.5kW. Rather then the extra go into the car, it was getting exported to the grid. So it would appear as though the software update essentially capped my charging rate at 4.5kW when I had ‘Charge Now’ selected. It appears to be working as expected when set to ‘Matching solar export’.