ToeKnee

A small investment in an Energy Monitoring device will be the best start. (I used IAMMETER), which gave me a really good idea of my overall load and when it happened. I then sized my Solar using that data - 5.4kW Panels - 5KVA Sunsynk and 15kW batteries. I added one additional 5kW battery, but I could have got by with 10kW. Did the install with Geysers and oven off the Solar and all the lights and plugs on Solar. I now have a good history after 3 months as to my solar demand and the amount of solar I generate across the day (and when my panels go into "sleep mode" when there is a small load. With that data I can now add the two Geysers onto the Solar side and comfortably heat them in the afternoon for 5 hours when my load never goes over 500w and then in the early morning (4am - 6am) to run the battery down from 70% to around 30%. One geyser is on Geyserwise so I can set the on/off times with the power and the other geyser will be connected to Smart Wifi Geyser Switch. That way the only thing will be the Oven and for that I need to read up more on the Grid Bypass and its possibilities. But that is way down the line (The stove is Gas)

If you only want to run plugs and lights 5kVA will work. If you want a Geyser operational, then 8kVA may be the best option for rainy days. My loads are very light at night (.25kw as a max) and with 15kW of batteries, I will be moving my Geyser onto the Solar side, with my Geyserwise set up to heat up between 3am and 5am My SOC never gets below 70%, so there is a lot available there.

My (limited) experience with Sunsynk makes it my recommendation. Easy Interface and relatively simple to change the settings as you become more experienced with the system. If you need an 8kVA Inverter, the 10KW of batteries may be a bit shy when you want to run off solar (if that ever happens) But if you just want plugs and lights, you could save a few pennies by a 5kVA Inverter. (if you think solar will never happen)

If your non essentials are been fed from the battery, then in all probability the connection at your DB is incorrect. It would mean that the non essentials are been fed through the Essentials side of the system. I assume that you turned the oven on - saw the discharge: turned it off and saw the discharge stop: The Installer needs to correct it - in my view

I purchased one of these Works like a dream and I use it to work out when to switch my geysers on to get the max out of my solar.

My Settings if it will help for Grid

I was quoted just sort of R35,000 for a 8KW

Logically if wired correctly on your DB, it should not use units from the prepaid. There is a small usage that comes through even when you are generating solar fully for the load as it has to ensure the frequency of the grid is followed. This is logic as opposed to real world, but there would have been a lot more written on this if it was a major issue

Is it possible to clarify something: The AUX function? From what I can gather, it is a function that bypasses the Inverter, and can use the panels to power a Geyser (or 2) ? I have 4.8kw Panels, Sunsynk 5.5kw Hybrid Inverter and 15kw (3x5) batteries. I would like to put my Geysers - I have 2 - on a CBI Smartswitch and set the geysers to run (2KW each) once the SOC reaches 100% (circa 10am at current loads) Am I correct in understanding, by using the AUX, if the load exceeds the 5KW at any time, it defaults to Battery/Grid to take the additional load? It is my first month with the system and I recently learnt from this forum how not to charge the Batteries using the grid at night Hoping for the next step in optimisation