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I have taken an interest to understand the Axpert display parameters and what they actually mean. I took the display at about 09:40hrs. Select parameters as follows:

Charging Current? (Is this a generation of the MPPT Charger based on the adjustment in proportion to the voltage drop to match battery voltage i.e panel voltage to battery voltage or just the straight panel optimal operating current under NOCT less losses? The lowest panel NOCT Imp is 6.71A giving us 26.84A before losses. However, looking at the IV Curve of the lowest panel in the configuration at 600W/sqm irradiance and voltage of about 29V 5.5A is possible).

22A.JPG.70992cbab2148d2664daf14bc28d835d.JPG

Battery bank voltage? (at sunrise this is usually 48.7V from night use)

163737789_51VBATT.JPG.68133adfa4957daa531cdcc72ba5d359.JPG

Inverter PV draw? (1.44kW under balance for MPPT charger and load at the time. suggests battery load of 1.149W at 22A)

144kWh.JPG.f5cf32f7c5f04dcd867f689a04fd37e5.JPG

PV Voltage (This suggests 28V/panel under my current module configuration based on the lowest panel Vmp. The IV Curve shows approx 5.5A at this voltage on the 600W/sqm curve)

534541668_85VPV.JPG.674286c71aec2c501a01c862ad7fda12.JPG

Thought to ask to understand these readings.

IV Curve.png

STC-NOCT.png

13 hours ago, Kalito said:

Charging Current? (Is this...

22A.JPG.70992cbab2148d2664daf14bc28d835d.JPG

This is actually the net SCC (Solar Charge Controller) charge current, on the battery side. In other words, it's SCC output current less the estimated battery current to run the loads. The PV and AC indicators (you are showing just the PV indicator above) indicate charge sources contributing to this net charge current.

In line/bypass mode, the AC input supplies the load, so there is no battery current required to support the loads. In this case, this screen shows the combined charge current from AC and PV sources. Again, indicators show sources contributing to the total charge current.

13 hours ago, Kalito said:

Battery bank voltage? (at sunrise this is usually 48.7V from night use)

163737789_51VBATT.JPG.68133adfa4957daa531cdcc72ba5d359.JPG

This is always the measured battery voltage.

13 hours ago, Kalito said:

Inverter PV draw? 

144kWh.JPG.f5cf32f7c5f04dcd867f689a04fd37e5.JPG

This is actually the SCC output power on the battery side, not taking into account any battery current supporting the load. So this is SCC output current multiplied by the battery voltage. The PV panels will be producing a few percent more power than this, to supply the SCC losses.

13 hours ago, Kalito said:

PV Voltage (This suggests 28V/panel under my current module configuration...

534541668_85VPV.JPG.674286c71aec2c501a01c862ad7fda12.JPG

Yes, this is the voltage measured at the PV input. So the average panel voltage is this figure divided by the number of panels in each string; it looks like in your case, this is 3.

Lets say the efficiency of the SCC is 98% (maximum quoted in the specifications). So the PV input power is 1440/0.98 = 1470 W. So that's 1470/85 = 17.3 A total. It looks like you have three strings, so each string is contributing 17.3/3 = 5.8 A. So each panel is producing 5.8 A @ 28 V, or 5.8×28 = 162 W. That's a little more than the 600 W/m² curve indicates. Not unreasonable for 9:40 am.

13 hours ago, Kalito said:

Thought to ask to understand these readings.

Yes, it would be nice if the manuals described these things in detail.

  • Author

I love the ability to independently display what I desire on the screen. I have a question though, I noticed that the PV icon would fill up depending on how much is coming in. Does the software somewhat display what is coming out of the panel like a graphical gauge? Very nice am loving the new firmware and the fans seem to be behaving differently i.e I can hear them running as the draw comes in more audible than stock firmware.

patchedfirmware.jpg.d1c675207ad38e2cb5e0543f1fd0936b.jpgPatcheddisplay.jpg.0f958f112e9a14ca58ba02dc2f423428.jpg

  • 2 weeks later...
On 2018/10/06 at 6:28 PM, Kalito said:

I have a question though, I noticed that the PV icon would fill up depending on how much is coming in. Does the software somewhat display what is coming out of the panel like a graphical gauge?

Yes. There is a manual in the 73.00c zip file you downloaded. You can also see it here: http://dkeenan.com/AussieView Manual.txt

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