KevinM

That would seem logical at first but keep in mind that air is 800X less dense than water so even a leak that causes a tiny drop of water to come out would let in over 800X more air by volume when sucking. Density of air - Wikipedia
https://en.wikipedia.org/wiki/Density_of_air#:~:text=At%20101.325%20kPa%20(abs)%20and%2015%20°C%20(59,International%20Standard%20Atmosphere%20(ISA).

I have been running a dual Axpert 5KW system for three years with 3 X Pylontech US3000(b) and 21X335W JA (7KW) panels. I was really hoping that the inverters would do me for 7 years which is essentially break-even from a financial aspect. Our average usage is 35KW/day of which 70%+ comes from the sun. So that works out to about R1800 savings/months. The system is self-installed and cost R180000.  (For those trying to figure out the math's here, keep in mind that in six years price/unit will have doubled)
The Axpert' started to give hassle's late last year and I had to replace one of the MPPT's. System was running at half mask for about 2 months. It has not been the same since then. ICC/SMH, off grid/on grid, battery management it’s all just not working like it used to.
In March 2022, during a clear sunny day and no-load sheading all three batteries BMS's blew. I returned them to my supplier who sent them in for repairs. I got one battery back about three weeks ago. I'm still waiting for the other two! Solar and Inverter warehouse (thanks Carl and Gary) were kind enough to loan me a second battery in the meantime. But what is worrying me is what caused the Pylontech batterie's to fail in the first place.
Without an answer on what blew all three of the Pylontechs’ I have become somewhat suspicious of the Axpert based machines. Three years’ service is undesirable. Sure, at times they were running at around 7 or 8 KW together for a few hours during full sun but It’s a 10KW system.
I am now seriously considering replacing them with an 8 or 16KW Deye or Sunsynk.
Here are my reasons:
1) The continued use of the Axperts' may degrade my expensive Pylontech batteries prematurely and possibly invalidate the 10-year warranty.
2) Deye/Sunsynk use IGBT’s as their engines versus less robust mosfets in the Axpert.
3) The Deye/Sunsynk carries a 5-year warranty, Axpert at best is 2 years to my knowledge.
4) Should you go over specification in the Deye/Sunsynk during a power outage, they apparently trip, the Axpert just keeps going until external delayed action of the CB's trip at 32A or the 100A battery CB trips or the battery itself trips. This can so easily happen when a cloud appears.
5) No monthly fee for 3rd party remote access and control for the LiFePO batteries.
Being a Hybrid and bidirectional it is true that the Deye/Sunsynk is in a different league compared to the Axpert type off grid inverter but does come at near double the price KW for KW.
From the onset I have noted that the Sunsynk seems to be well supported locally in South Africa whereas the Deye only has "word of mouth" support.
Hardware-wise they are the same unit. Keith Gough, CEO of Synsynk has done a fantastic job of marketing Sunsynk. And their HQ office in SA is in Randburg. Sunsynk does however come at a around a R5k premium over the Deye.
I would appreciate any comment regarding my analysis but also if the extra price of the Sunsynk is worth it over the Deye.  
Also, should I be looking at 1 X 16KW unit or 2 X 8KW units or is 1 X 8KW enough. This considering that the arrival of electric vehicles is imminent?

Hi, and welcome to the forum. 
1. Each inverter will have it's own set of panels. 3 string on the one and 4 string on the other would be fine. 
2. You need to use DC surge protection Type 1 and 2, depending on your are, for the panels. They're more expensive though and come in 600V or 1000V variants. 
3. Yes, as long as you install as per regulations and sign a COC for it.