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edphonse avatar image
edphonse asked

Smart Solar 150/100 Not Operating at 100% capacity of solar panels

So I finally resolved my last issue with my Smart Solar displaying the correct battery voltage on the main screen but incorrect voltages in the history page.

The first day I ran the whole system (2x Smart Solar 150/100 MPPT, 1x Lynx shunt +power-in/distributor, 2x 12v multiplus 3000 in parallel, and 4x Battleborn Li-Ion batteries) it ran great. Each controller has 8x 100 watt renogy panels (2x set of 4 panels in series ~80v open voltage) per controller. The first day one controller peaked out at 880 watts (it was a very cold day so the panels were more efficient since its rated at 100 watts at 25C), the other controller peaked out at 840 watts. The next day my Cerbo GX and Touch display came in so I shut the system down, plugged in the VE.Can and VE.Bus to the respective units and made the minimum entries into the Cerbo to get it going (IE wifi set up, VRM set up, 400 Ah battery capacity). Ever since then the controller REFUSE to put out more than 75% of the panel rated power, regardless of how many panels I have connected to the controller and regardless of the series/parallel set up (IE 4x in series was putting out 300 watts, 6x in series was putting out about 450 watts, 8x in a 4:2 Series:parallel would put out about 600 watts) and BOTH controller do this.

This has been going on for a week and as more time goes on the VRM logging (every 1 minute) is showing more and more dips through the day even though it is almost always sunny out where I live.

I even shut the whole system down for a day and brought up the inverters and discharged the batteries to about 80% then turned the solar controllers back on, reset them to their defaults, reassigned the battery to Li-ion, and got exactly the same results.

I also don't think the cables running from the solar panels to the controllers are the issue. Each controller has 1 positive and 1 negative running to their own set of panels. Used 10 AWG wiring and the run is around 100 ft from panels to controller. The controller then has 2 AWG to connect to the lynx system and 4/0 for battery/inverter connections.

Does anyone know why when I plugged in my Cerbo GX that the system just basically stopped working at 100%?

Edit:added photos of the history display on both controllers the two lowest peak power days were cloudy but every other day was basically 100% sun.

MPPT Controllers
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1 Answer
Jaco Reinecke avatar image
Jaco Reinecke answered ·

Hi,

Reading fast through your question, my first thought was that the two MPPT's are "arguing" with each other, i.e. one takes the lead, the other one does nothing, or very little, idles.

Are both MPPT's settings identical?

Just spitballing here ...

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edphonse avatar image edphonse commented ·

Both controllers are programmed according the Battleborn's recommendations. 14.4 V bulk/absorb and 13.5 volt float. Perkuert exponent, charge efficiencies, and tail current I have all programmed to what I found recommended for MPPTs for Li-Ion batteries.

I have even tried running only one controller at a time and got the same results, so they aren't fighting each other. Something changed with the MPPTs when I plugged my Cerbo GX in and I couldn't find any settings that would have interfered with that. I currently have the Cerbo GX disconnected from the system and still get the same results when only running the inverters and MPPTs.

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