DirkBal

I live in an apartment, so I don't use the solar charge controller.  I just use it as backup when Eskom fails.
My light circuit and a "red plugs" in ever room of the apartment are fed from the inverter.  Been running like that since roughly 2014, I switched to an Axpert King in 2018 (If I recall correctly) for the double conversion, I have a lot of computers and stuff I didn't want damaged by Eskom's sh!tty supply.
I power my TV, router, microwave, kettle, Nespresso, fridge, TV, amplifier for TV, NAS, home office from the Axpert, occasionally things like vacuum if there is load shedding and the place needs cleaning.
The Axpert King runs in inverter mode 24/7 and it has held up well, when I turn on the kettle or microwave the fan speed increases but it is pretty much drowned out by the noise those appliances makes.  Everything else it remains fairly quiet (so not much load).  I rarely go above 3.5kW.
Different brands may have different models.  You can look at the models available here: http://voltronicpower.com/
Voltronic Power makes the actual inverter and then puts the badge on the seller wants.  There are companies that manufacture clone Axpert inverters, meaning they actually copied the design.  They took an already low cost inverter and went cheap on it, so you can guess the end result of that.
My 2c: Buy your inverter here https://www.fullcirclesolar.co.za/
I've bought a few from them, they are the cheapest I could find, respond quickly and they don't sell fakes.

I had the same problem with a Infisolar V series, dropped bulk charge to 52.8V and float to 52.2V and have had no recurrence of the problem.
Hope this helps you too.
 

Great info thread, thanks guys.