Woke up to blank SCC and drained batteries, now won't charge

[lflock]

Good to know.

This time of year, your 600W array is going to perform like a 400W array. As the days get shorter and the sun moves farther South, flat performs worse and worse. In about 6 weeks, it will perform like a 300W array.

Is any part of any panel even slightly shaded any time between sunrise and sunset?

Based on a 1.5kWh/day burn between fridge and inverter, 400W is marginal.

Can you give me a nearby city?

Nearest big city is Leon. The highest my SCC has shown is around 550w, most of the time it 450-470watts. The panels are not shaded at all.

 

[lflock]

The default charge setting for lithium in your Rich controller is far from deal if you wish for daytime solar to augment your power use.

Are you connecting your system to the controller load outputs or direct to the batteries?

What batteries do you have, the kit given in the link, suggests AGM batteries?

I have 2 lifepo4 100ah batteries. The panels go into the charger and the charger is hooked up to the batteries, the batteries to the inverter.

 

[lflock]

 

[Partimewages]

You will have some panel de-rating if it's very warm.

 

[sunshine_eggo]

Nearest big city is Leon. The highest my SCC has shown is around 550w, most of the time it 450-470watts. The panels are not shaded at all.

You're pretty far south. That mitigates the impact of flat panels. This time of year you should be able to get 2.5-3.0kWh pretty easily with clear skies.

Battery wiring.

With your parallel batteries, all (-) connections should be made to one of the two batteries with all (+) connections made to the other battery. Your inverter appears to be connected only to one battery, and I can't see where the charge controller connects.

You must draw "across" both batteries to have even load sharing.

 

[Checkthisout]

View attachment 176019

Unrelated to your issue but do not lay the charge controller on its back like that.

It WILL eventually burn itself out.

 

[400bird]

Okay, figured out BMS is battery management system, but doesn't the SCC do the same thing, essentially? Or, do I need one?

A battery management system's one job is to protect the cells from things like over voltage, under voltage, too much current, high, and low temps. (Many low end BMSs leave off the temperature part)
The BMS is integrated

A solar charge controller turns energy (at a higher voltage) from your solar panels into a voltage suitable to charge your battery.

There really isn't any overlap here and both are required to do each job.

Nearly all BMSs integrate a current sensor and coulomb counting to provide a more accurate SOC. Most charge controllers just use voltage and provide garbage data for SOC. The SOC from your SSC actively gives bad data. Don't trust it.

If you don't have like a Bluetooth app to the BMS in your batteries, you can get a shunt or battery monitor to connect in line with the battery to calculate a usable SOC.

 

[JWLV]

Keep in mind that whatever voltage you are seeing, whether from your charge controller or from a multimeter, is going to have a margin of error.
The reason is all batteries will measure a lower voltage whenever there is a load on it. The larger the load, the more the voltage gets dragged down. As an example, a battery with no load on it may read 13.5V. Connect a load and the same battery might read 12.9V. The difference could be more exaggerated with a small battery (100AH is rather small) or with a larger load.

That said, a 100% SOC battery may show 12.9V when under load. It could also show 13.5V when not under load.