Denarius

Does the VM III have solar utility blending when a battery is connected? As far as I know the axpert king can blend with battery. I know at least my mks ii can't blend with battery connected, but it can blend without battery (see original conversation of this thread). Since I can't blend, I converted my 4kw geyser to 2kw so my 12 panels can power it without draining battery. I run a geyser timer to make sure they are only on mid day, with temp set to 65+ so it's hot enough the next morning even if you use hot water at night. I have 2 geysers which run after each other.

Looks normal to me. I have 12x JA solar 340w. See attached for the generation today (yellow). I get about 3.4kw constant at best, although it sometimes spikes to 6kw or even more for a moment.

Looking at the King manual I guess one disadvantage of King is a solar voltage is 60VDC~115VDC while MKS II is 120VDC~430VDC. So with the king you will wire more panels in parallel.

@Gnome Does FastCGI somehow make it more robust? I'm thinking of using your inner C code in a Ruby gem, so that part would be a C extension in the gem. Any thoughts?

I also thought about extracting the inner C code so that I don't have to use FCGI, etc. It seems like the FCGI layer handles timeouts and the author previously made two other connectors so perhaps he is using FCGI with good reason. I'll try and find out from the author.

Just checked and saw it's the VMIII that doesn't have parallel operation. My bad.

Have you seen this new repository? The author claims it's solid communication to axperts via USB. Since you have tried various things, what do you think of his approach? https://powerforum.co.za/topic/5394-axpert-software/

For PylonTech I think we can extract code from the repository below. I'm currently running ICC but I'm thinking of developing something open source that supports axpert and pylon techs, has a small control panel and can submit data via MQTT to home assistant or smart things. Then people don't have to pay 3k+ for ICC which becomes unresponsive in various situations. https://github.com/celsworth/lxp-pylon-utils

Disadvantage of King is you can't run multiple units in parallel, so if you buy 5kW then that is your max with no option to upgrade. If you run the MKS II then you can parallel lots of them, but you don't have solar and grid blending as mentioned. What does that mean exactly? When solar + battery isn't enough to power your loads then the grid will fully power the load while the solar charges the battery. Another scenario is let's say you run geysers in the middle of the day and during that time you want to augment solar with grid instead of battery to put less strain on battery: can't do that with MKS II.

How did you do the 2 way MQTT communication with axpert inverter? Is it available on github somewhere?

Gnome looking at your other repo it seems like you have excellent knowledge of the various Axpert commands. If you can create a Ruby gem that calls this new axpert HTTP lib you made then we have a solid easy API for Ruby. I'm a Ruby web dev that run 2x Axperts, pylon tech batteries and ICC software.

Since hybrid inverters are more expensive you usually have less kW. An example is you only have 5kW instead of 10kW. You mostly avoid this limitation since hybrids allow you to split your load into the essential load (supported via battery backup) and the rest. The output limit (5kW as an example) only applies to the essential load while the rest can still be powered by solar. This sounds great, but note the following considerations: 1) When the grid is down the non-essential load will be down regardless if there is enough solar or not. 2) Certain devices like lawn mowers cause a spike when they start and could be hard to take out of your essential load since they can be plugged in anywhere. 3) Solar can be very spikey. When your solar output drops lets say to 2kW while you have a 3kW geyser pulling from the non-essential load the 1kW will come from the grid. If you were using the 2x MKS II your geysers will also be on battery backup and therefore it will discharge the battery to get the 1kW and not use the grid. The battery effectively acts as a buffer for the solar spikes and reduces overall grid usage. If you don't mind using the grid here and there then hybrid is perfect. Downside for geysers on MKS II is that low solar + load shedding can drain batteries quick and become an issue (I use geyser timers to avoid this issue). 4) I have 12 panels which should provide 4kw of power. They spike up to 7kw when connected to 2x MKS II because they can handle 7kw. When connected to an inverter that can only handle 5kW, they only spike up to 5kW. Still overall I think the hybrids are probably better for most people.

1) If battery levels drop too low the entire load is switched to utility while the solar charges the batteries. So no power is wasted. 2) Correct.

I run 2 of these Axpert MKS VII in parallel with the ICC control module. It seems like the PV can't be blended with grid if you have batteries connected. Under "operating modes" the manual also specifically states "and battery is not connected": This effectively means that it is not possible to achieve a SUB (Solar Utility Battery) mode or setting.

It sounds like your expectation is that it switches between PV and Utility instead of using both at the same time like hybrid or grid tie inverters. If that is the case then I agree it isn't very useful. They do however mention the words "at the same time" in the manual, the same words they use to describe how solar and battery works together.

It's popular knowledge that the Axpert MKS switches over to grid completely if the load is too much for solar and optional battery. It doesn't supplement it's solar with grid. This video describes what I'm referring to: https://www.youtube.com/watch?v=n6DVS8lLgjw However, with the latest MKS II the marketing material of the various companies that white label the product mention this: google search phrase below This makes me expect that there is a "SUB" mode as described in the very similar Axpert King manual (shown below). However I don't see it in the MKS II manual. https://portal.segensolar.co.za/reseller/docs/Axpert-KING-manual-NEW.pdf Does anyone know anything about this new mode referred to in the marketing material?