SmartSolar 75/15, running firmware 1.39. 2 x 100w 12v panels in series. 6 foot wire run, 12 gauge pure copper, all MC4 connectors tight and snapped, as they've been for years.
I just observed this a second ago, lifepo4 battery floating mid-day at 13.35v. I disabled the charger from the 75/15 battery settings, and then re-enabled it a minute later. This was in nearly full sun.
What I observed was that upon enabling the charger, the PV voltage went from 40-something to ~15, then back to 40, back to ~15 over and over again for about 10 seconds. After that 10 or so seconds, it returned to high voltage and producing a consistent 160w. The battery quickly went to absorption and then float.
I've never seen this before. If my wiring is bad, it seems unlikely that it would have sorted itself out 10 seconds later and started to produce at a pleasing 160w. But I also don't know what mechanism if any could be responsible for this in the charge controller. Any advice appreciated, and if this is normal behavior please let me know! Reconnecting charge when the sun is fully out is the opposite of what naturally happens in a day/night cycle so perhaps that's the reason it did this?