Good evening

I am seeking advice on our installed solar system, pictures added for clarity.

So we have a 5kVa inverter with 8x 100Ah gel batteries (4 of them connected in series with the other 4 in parallel) and 8 panels (330W)

The picture titled Inverter_2.png was taken today at 17:00 at which point there wasn't really much charge coming into the batteries, should I be concerned that the battery is only displaying 2 bars at 52.3V after a full clear sky sunny day?

Regards.

Hard to comment without knowing what your daily power consumption is. Your 8 panels x 330W, i.o.w. 2640W, call it 2.64kW, might generate around 10-12kWh (units) of energy per day this time of the year. Its quite plausible that a third of that of that was consumed by baseload consumers during the day, maybe another third by spikes for household appliances being run, factor in some losses in the conversion and storage, leaving just under 4kWh of available power to raise the state-of-charge of your batteries from 20% to 60%, ie 40% of 9.6kWh theoretical storage in those batteries. All thumbsucks and ballpark figures, probably best to measure.

9 hours ago, Aidy93 said:

pictures added for clarity.

Welcome. Thanks for the pictures; they save a lot of time.

9 hours ago, Aidy93 said:

So we have a 5kVa inverter

Your inverter appears to be a clone. So it's hard to say what its exact behaviour is going to be.

Quote

with 8x 100Ah gel batteries

I note that they don't appear to be connected properly; the set in the foreground will not work as hard as the set at the back. You should move one of the cables to the inverter to the front set, for a diagonal connection. That will let your back battery modules last longer.

9 hours ago, Aidy93 said:

The picture titled Inverter_2.png was taken today at 17:00 at which point there wasn't really much charge coming into the batteries, should I be concerned that the battery is only displaying 2 bars at 52.3V after a full clear sky sunny day?

Yes. It means that even on the best days, your battery is not getting fully charged. The battery State Of Charge display on these inverters (presuming a faithful copy of the Axperts) is not great, but also not terrible for lead-acid batteries like yours.

It seems that with the battery at 53.2 V (an average of just over 13 V per 12 V module), the battery is not charging. You could well be suffering from the premature float bugs. Your clone seems to be an early one; Axperts exceeded this specification in about 2015. That means it's less likely to be able to have its firmware updated. If you are suffering from one of the premature float bugs but can't update firmware, you'll need to try one of the workarounds. The trouble is, both of the work-arounds require reasonable modern firmware, with facilities for timed absorbtion, or equalisation.

You should watch the middle CHG LED and report when it stops flashing on a good solar day. That will tell us when the charger has gone to the float stage.

You are also a bit low on panel power, you could do with another pair of panels (I assume that your panels are connected 2S4P). It looks like you have room for 2 more. That will bring you to 10% over 3 kW of panels, which is its rated power (shown as rated "current").

If you don't correct these problems, your battery life will be cut short, perhaps to a few months or a year at best.