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Solar PV watts drops to zero?


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Any suggestions on what can cause this and how to rectify it? It happens infrequently, last happened 6 days ago. System is running well and then all of a sudden my PV Watts fall away although the voltage still shows. I have a 5kva Voltex King with 10kW Lithium batteries and 12 x 300W Pv's, 3 per string.

PV zero watts.JPG

ICC Setting.JPG

Edited by KobusC
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I note that the battery voltage is 49.6 V. My guess is that you had a brief surge of load demand (e.g. fridge starting up, or something with a larger surge) that momentarily dropped the battery voltage to 45.0 V, where the battery is declared "weak". That's because it's 2.0 V above the DC low cutoff voltage, or setting 12 (back to grid voltage); in this case they are the same (45.0 V). At that point, charging stops for several minutes (perhaps to let the battery voltage stabilise), then a bulk charge is commenced again. Monitoring software can only poll the battery voltage every 5-10 seconds, so it's often not going to show up in logs. Factory firmware makes no effort to compensate for load power when making these decisions based on battery voltage.

But if the PV charging stops for longer than a few minutes, then you're suffering from "dips". Sometimes, these dips last to the end of the day, when they become "freezes". Firmware from about 2019 onwards, and possibly particularly Kings, seem to suffer from this problem, and there doesn't seem to be a solution at present, at least not one that has been verified by users. For example, see this topic; there are several topics discussing this issue.

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1 hour ago, DeepBass9 said:

Batteries full?

Screen shot shows 64% SOC, and a battery voltage way under the float voltage setting.

1 hour ago, DeepBass9 said:

Inverter switched to grid?

Screen shot shows grid power as zero, load power as 470 W.

1 hour ago, DeepBass9 said:

Bad connection to panels moving in the wind?

PV voltage shows as 114.6 V.

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