SmartSolar not charging in full sun intermittently?

Working with a new SmartSolar 100/20 controller in a simple system with a single 12v AGM and a single 100W panel. The load is a small DC refrigerator. Also using the Smart voltage and temperature probe.

I notice on occasion I'm not getting any charge (2-4W panel yield) despite full sun on the panel (and a high voltage at the panel) while a load of 5.5A is drawn from the load output on the MPPT. Then for seemingly no reason charging will resume either when the load has shut off or it just jumps back up to 70-90W for no noticeable reason.

Is this related to charging modes? Temperature? A fault?

I really like this controller a lot but don't trust this behavior without understanding whats up.

Thanks for any insight,

2 |3000

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klim8skeptic ♦ commented · Jul 22, 2020 at 01:13 AM

Are your batteries really that hot? 63c

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amos5000 klim8skeptic ♦ commented · Jul 22, 2020 at 01:57 PM

Yes, sometimes the temperatures are quite high. The battery is in the engine compartment of my Land Cruiser.

For this testing and observation the system is not tied into the vehicle systems but isolated.

Looking at more information this does seem like a control fault as the settings explain the charger should switch back to bulk if the voltage is under the threshold for 1 minute or more. With a threshold of 13.4 volts it should not sit in full sun not charging at 12.9 volts for several minutes as I've been observing.

I guess next time I observe I'll try to manually re-start the charger and see if that works... firmware is v1.50

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