Asistance troubleshooting my EcoWorthy system?

[MuGGzy]

I bought a Eco Worthy "kit" and had a electrician install it (the electrician recommended this kit). Initially the contractor told us he was "their solar guy" and did the install. When it didn't work and we had him come back he admitted that he really only did grid connected systems and had never worked on or set up the system he picked and recommended to us. So he spent the whole day poking at buttons and said it was all good.
That night we were able to run the things we wanted and my CPAP worked all night so we thought it was cool Before we leave we shut off the breaker
between the system and the cabin so there is no risk of us accidentally leaving something on and draining it while we are gone.

This last weekend we got there and I checked the system right off and for some reason the battery bank was only 75% full, which I thought was weird, with 2-3 weeks to charge I thought it should be maxed out.
We went inside and plugged in an IPad to charge and a small lamp, both worked fine, but after about 5-6 hours suddenly everything turned off and I went to check the system and it showed the battery was down to 1 bar and the output was turned off so the battery could charge.

This seems like very poor performance to me. I thought about calling the contractor again but since he admitted he was just on Google trying to find setup info on our system and "just trying to figure it out", I have doubts that he will be able to do much better than I can.

We have:
Eco Worthy 3000W Inverter
4X 25.6v 100Ah batteries in parallel
6 panels on the roof

Any ideas on where I can start looking for the cause? Is something draining the batteries even when nothing is connected to the output?
Is the inverter not actually charging the batteries?

 

[meetyg]

How do you know that the battery was 75% full? Is that based on the LCD display of the inverter? If so, that's not a reliable source of state of charge (SOC). They are calibrated for Lead-acid batteries, which have a fairly linear voltage curve. Lifepo4 has a mainly flat voltage curve throughout most the capacity.

But I agree that if there weren't any loads and solar was charging while you were out, the battery should have been fully charged.

 

[Mattb4]

Yes there is something draining the batteries. Your AIO likely draws ~50W at idle. Over a day that can add up to 1200Wh or 50Ah from your batteries. Unless that is made up each day from your solar panels it eventually results in draining your batteries. One way to address this is to turn off the AC output ( On/off switch) of your AIO if it is one of the models that can continue to charge the battery from PV while the switch is off. Another possibility is to switch to Eco or energy saving mode in the settings. Eco mode reduces idle draw substantially but requires a 200W load before it turns on the inverter.

 

[MuGGzy]

How do you know that the battery was 75% full? Is that based on the LCD display of the inverter? If so, that's not a reliable source of state of charge (SOC). They are calibrated for Lead-acid batteries, which have a fairly linear voltage curve. Lifepo4 has a mainly flat voltage curve throughout most the capacity.

But I agree that if there weren't any loads and solar was charging while you were out, the battery should have been fully charged.

Ya I was just going by the little icon on the display that shows the battery filling up. I know it's far from precise but figured it should be somewhat close.