Peter le Roux

I see no huge problem with this, maybe just limit the charge rate to 1kW or less to limit how quickly they'd be up at full charge again...
LiIon NMC type battery cells will  be 100% happy, disconnected at 50% charge, but, then the BMS comes in, consumes some juice, not much, but trickling electrons away over time, the 18650 and similar cells NMC type LiIon cells, stored disconnected are perfect in a 50% charge state and 2 years later will function fine generally, not sure what LiFePO4 cells would like, but since a BMS is involved that will consume some power, it becomes a different scenario anyway...
So. I'd say, limit the charge current to less than 1kW/20A and let the system run, just keep an eye on it, maybe once in the morning and once after sunset to see whether its doing what you're expecting...

Yesterday was a bad day for solar but with the help of a constant load this afternoon and some cloud edge effect in the morning I managed 6,5x installed wattage for production today. some nice peaks at 6+kW this morning from my 5,5kWp array:

Yesterday was a bad day for solar but with the help of a constant load this afternoon and some cloud edge effect in the morning I managed 6,5x installed wattage for production today. some nice peaks at 6+kW this morning from my 5,5kWp array:

I'm gona also throw something into the mix here. When I provide an estimate for an installation I also insist on doing a site visit. It provides me a means to see what sort of challenges a site will present & also allow me to familiarise myself as the installer with the needs of the client. 
So off the bat, slate roofs cost more in labour, for obvious reasons. They are labour intensive, involve extra pieces of roof tiles as well as Bitumen. Usually if a specialist roofer is called in it will cost an additional R6k odd for them to do what is required. We offer this in house as we have worked on many Slate roofs so we guarantee that the roof will be sealed as good as we found it before. I have a slate customer as far a field as Hilton on this forum where is rains a lot. His roof is still sealed post installation. 
A 2 storey home also costs more, simply because the labour takes longer & safety on this roof is paramount. Also some roofs allow us to work with Scissors lifts etc & this is also costed into the project. We have access heights up to 30m. 
Flat roofs as much as they are great to work on also require more extensive labour because the Block ballast that weighs 35kg each takes back breaking amounts of energy & a scissors lift to transport to the top. 
Roof safety is paramount for my team & I. I also don't install in a day because I enjoy the work to come out right. Done right the first time. This takes time & thought. We are not the 1 day Bakkie brigade. I'm sorry if you want a one day band then that's something you will find a plenty but the time & patience taken has usually paid off. I haven't had a customer not happy with our installation yet. The installation must be functional, look great & most importantly safe. 
So I don't think you can get a one size fits all. Another aspect I see sorely lacking in this installation business is competent User interface installers. Post installation on one of my sites I take ownership of Comms between Batteries & inverters etc. I support you with the equipment should anything go pop. Sunsynk, FreedomWon, Deye, ATESS it doesn't matter. I will not install a piece of equipment from a questionable source & I will act on your behalf to get the best solution & outcome. This is surely the role of an installer. 
 

6.8 kWh from 7.8kW  array , worst I had in years . But really happy with the rain we had . Some areas 70 days without water.

Is the HVAC 24000W or 24000BTU? 24kW is enormous for a home AC. 24000BTU is more like 8-10kw which is still more than your capacity but closer to being workable

You need to use the 'true'/sidereal/solar direction and not the magnetic direction

I'd say add more panels to your solar and then power the geyser via the inverter. This is what I will be doing, although with a geyser timer to turn the geyser on in the afternoon after batteries have been charged and the load is reduced.

In theoretical terms, direct solar heating of your water with a solar geyser is more efficient because you are turning solar radiation straight into hot water without the intermediate steps of AC->DC->heat in the element.
BUT
once your water is hot, there is nothing else that you can use that solar geyser for. If you add extra panels, once you have heated your water, you can use the solar panel to charge batteries or run other appliances in your house.

I had the same problem . I cut with using baby angle grinder with diamond cutting disc in situ.   Problem is dust ,  but just deal with it 

It can be cut. The granite installers use a water-cooled diamond saw to do the cuts. Very dusty and messy job but it is quick. Depending on the location, they might need to remove the counter top and replace and re-do the epoxy joints once they are done

It can be cut. The granite installers use a water-cooled diamond saw to do the cuts. Very dusty and messy job but it is quick. Depending on the location, they might need to remove the counter top and replace and re-do the epoxy joints once they are done

For charging, the cheapest hardware (R70) would be a small buck/boost regulator like this:
https://www.communica.co.za/products/hkd-dc-dc-buck-boost-1-25-35v-4a?variant=44293669519660

You would need to place this into your own small enclosure and you would need a multimeter to adjust the pre-set potentiometer to give you an output of 13.85V to float charge a 7Ah SLA battery.

An even better module would be this R340 buck/boost regulator:
https://www.communica.co.za/products/dgm-buck-boost-solar-1-30vdc-10a?variant=19665729519689

The advantage with the more expensive regulator is that you can adjust the output current limit.  With this you could charge small lithium batteries as well.

Both regulators can boost the voltage, so you could even charge 6V and small 24V batteries.
They are both switching regulators so you can expect about 85-90% typical efficiency, which would be much better than a PWM charger.

Maybe something even smaller like the options below. But basically yes, it could be used to keep smaller-sized 12V batteries topped up. For alarm batteries, gate motors, DC lighting, charging phones with USB or car charger, small DC circulation pump, etc.
https://solarequipment.co.za/product/bluesolar-pwm-light-charge-controller-12-24v-5a/
https://www.sustainable.co.za/products/epsolar-landstar-0512eu-5a-12v-pwm-charge-controller?variant=40898778136769&currency=ZAR&utm_medium=product_sync&utm_source=google&utm_content=sag_organic&utm_campaign=sag_organic&gclid=EAIaIQobChMIkrbBpOua_wIVxOvtCh3l1AN_EAQYASABEgKf9_D_BwE
 

In the current climate a journey might end up in frustration. 
Just look around and see how many households are still hoping for things to improve after 15yrs of LS. 
Once we get to stage 8 on a regular basis I see a lot more scrambling to get inverters, panels and batteries. 
Just do it now than to wait until you can get the heart of your end state. 
In order to get a good working scalable system does not mean you have to always be in fashion. Older panels of the needed rating can work just as well. Yes you might need more. 
A friend mentioned the other day that below 455W panels are not in fashion. I just keep quiet with my 270W panels performing very well for my needs although some are 4 yrs old. 
I can go and get similar panels in stock at sellers. Not in fashion 🤔🤔

Here is my experience and lessons learnt through my journey thus far.
I will say first where I want to end up as an end goal, and then the route I took, thus far in getting there.
End goal:
1. 6000w solar solution (Bar off course gloomy days), but having on a reasonable day be able to draw 3000w from solar.
2. Inverter that can match at least 4kw drawn at any given time, but be able to go lightly higher when required, but not more than 6kw.
3. Batteries that can sustain my house for at least two days without any grid or solar coming in.
 
Journey:
Step 1 was just to cover me for loadshedding, so I got 100ah 48V system, inverter, 8kva 6000W, and gel batteries, these did what I initially wanted, but the gel was a bad call, unfortunately, budget didnt allow for LSP straight off the bat, so I was okay with that.
Next was Solar, but once again budget was an issue and here my biggest lesson, I went with lesser panels, full power, rather than better panels half power, with expansion later. If I could do it over again I would have gotten top notch panels with output only 3kw rather than lesser panels 5kw, cause now the panels are absolutely crap. With my initial budget I could have easily gotten 5 panels of the best money could buy, water under the bridge now. Lesson learnt, I wanted it all and got nothing. So rather look at your budget and get the proper stuff even if it means less of it, for now, you can add later and never feel sorry. Also going with the proper stuff means you will find it later in order to expand.
I recently swopped the gel out for 5kw LSP, great change, fortunately the gel initiatially wasnt that expensive, 6k wasted but not totally and I will explain in a bit.
Next step on the right path:
1. Get another battery, pushing the backup up to 10kw - Half way
2. Swop out the panels for the right ones - Following the above approach - This time doing it right, if I dont have enough for 10 panels dont get 10, get 8, and add two more later, but for heaven sake dont get 10 lesser brand, this donkey wont stump its toe again
3. Add two more batteries and add panels if #2 above wasnt the full requirement met
4. Done
In Rand this is where I am at:
1. Inverter and original Gel battery solution - R17k
2. Solar panels - R 25k
3. New LSP - R 24k
4. Installations etc - R 5k
 
What is left:
1. New Solar - R45k
2. Added Batteries - R 72k
 
Ending up with 6000w Solar, 8kva 6000W inverter, and 21kw battery backup
Total cost for final solution:
12k + 96k + 45k + 5k = 158k
 
Now what I am doing with my current solar and gel batteries?
I have an external DB that feeds the outside of my house, Gates, Swimming pool and external lights. Max draw 800w, with pump running. Im going to get a small 1000w inverter and add this 1kw inverter to it. It already has the AC feed from internal DB, so this will feed into the new inverter, on that I will mount the old solar to my car port roof and then use my old gels as the battery backup (all these will do is keep the gates active and outside lights in time of loadshedding, well lights (10w) and the gates never work during the night anyway, so this way at least I utilize the old "mistakes", and also take some load away from my internal solution.
The other option is to maybe just give it to the church or such, as a good deed.
In a nutshell:
Dont go with less than what your end goal is, and if you dont have the funds, rather wait, but dont go with less and be sorry later.
 

I've been using a time for the past year with no issues - also frees up the aux port for a generator should you need it later