https://cs.jinkosolar.com/app/index.html#/customer-complaint/authenticity

Put your panels serial numbers through this verification just to be sure

On 2026/01/12 at 10:09 AM, Gandalf said:

On both of these systems the most those panels ever output is 1200w, nowhere near the 2460W they are rated for.

You have the 4 x Jinko panels connected 4S1P to Mppt 1? Yes. To take the guesswork out of the equation disconnect the 4 panels from the inverter and the string. At midday in full sun measure with a dmm the open curcuit voltage of each panel and dot it down. Compare to the Voc on rating sticker. Now by using a DC isolator short the leads of each panel and again dot the readings down and compare to rating sticker. Do the current test with a DC clamp meter most dmm has a max current rating of 10A. The current produced at ISC will tell you the capable wattage. Multiply the ISC (measured) with the Vmp on rating sticker that would be the maximum power the panel can produce. Your inverter will clip at 13A. I have found quite a few faulty panels(diffrent OEM) that limits the current on a string.

Edited January 20Jan 20 by TaliaB

On 2026/01/20 at 10:34 AM, TaliaB said:

You have the 4 x Jinko panels connected 4S1P to Mppt 1? Yes. To take the guesswork out of the equation disconnect the 4 panels from the inverter and the string. At midday in full sun measure with a dmm the open curcuit voltage of each panel and dot it down. Compare to the Voc on rating sticker. Now by using a DC isolator short the leads of each panel and again dot the readings down and compare to rating sticker. Do the current test with a DC clamp meter most dmm has a max current rating of 10A. The current produced at ISC will tell you the capable wattage. Multiply the ISC (measured) with the Vmp on rating sticker that would be the maximum power the panel can produce. Your inverter will clip at 13A. I have found quite a few faulty panels(diffrent OEM) that limits the current on a string.

Correct, 4S1P to MPPT 1. I haven't been able to get back to site to do these tests, but here is a screenshot from a few days ago with a 3.38Kw load and the panels giving "full' power at around midday. It was a sunny day. I will return as soon as possible to test each panel.

2 hours ago, Gandalf said:

here is a screenshot from a few days ago with a 3.38Kw load and the panels giving "full' power at around midday

The solar array is producing 50% of its capacity, the battery is 2.3kw towards the load. There is defenitely something wrong on your solar array.

4 hours ago, Gandalf said:

Correct, 4S1P to MPPT 1. I haven't been able to get back to site to do these tests, but here is a screenshot from a few days ago with a 3.38Kw load and the panels giving "full' power at around midday. It was a sunny day. I will return as soon as possible to test each panel.

Might mean nothing. Dont' know, just speculating.

I'm reading a Sofar hybrid manual off the web, and it says that "The HYD 3-6K-EP inverter has two MPPTs, which can operate independently or in parallel. The inverter can automatically identify the MPPT operating mode." And then elsewhere as troubleshooting for a PVConfig Error: "Check the PV input mode (parallel/independent mode) Settings for the inverter. If not, change the PV input mode."

Is there any chance that this MPPT parallel configuration feature/setting is causing the solar power to be capped to 50% of the rated capacity by throtting the current, as if it thinks only one MPPT is connected? Even if that's not it, I'm just thinking that 50% seems so non-random that it suggests there's an inverter setting somewhere that is causing this limit.

22 hours ago, GreenFields said:

Might mean nothing. Dont' know, just speculating.

I'm reading a Sofar hybrid manual off the web, and it says that "The HYD 3-6K-EP inverter has two MPPTs, which can operate independently or in parallel. The inverter can automatically identify the MPPT operating mode." And then elsewhere as troubleshooting for a PVConfig Error: "Check the PV input mode (parallel/independent mode) Settings for the inverter. If not, change the PV input mode."

Is there any chance that this MPPT parallel configuration feature/setting is causing the solar power to be capped to 50% of the rated capacity by throtting the current, as if it thinks only one MPPT is connected? Even if that's not it, I'm just thinking that 50% seems so non-random that it suggests there's an inverter setting somewhere that is causing this limit.

You could be onto something here. I did see that setting, but left it on the factory default assuming it would be fine. I will try change the setting to see if there is a difference. I agree that 50% output seems a rather odd clipping, as if a setting is wrong.