P1000

The primary problem is not the quality of the cells, it's that those batteries don't have balancers in them. I have considered buying ingco batteries to harvest the cells - they are currently the cheapest source locally.

yup, a while ago I saw 2ah ingco batteries advertised for R250.
that is R50 for a new high discharge cell. not bad...
I 100% agree with your statement that the cells are not bad quality, they just dont have a balancing circuit. And all the powertool batteries that I have salvaged from, its always either the bms or 1 cell(or 2 or 3 depends on the construction 3p5s, 2p5s, 3p10s...) that is faulty, if the battery pack have not been abused beyond recognition, and that led me to believe that the absence of a balancing circuit is causing the majority of the failures.
I add a small cheap 4.2v balancer to the packs I rebuild, iirc it only starts balancing at 4.17v at 60ma but it works, so far and it cost about R50

Some of those higher capacity batteries have non-standard discharge curves. From those that I have looked at, all the extra capacity was below the voltage cutoff for the BMSs I could get, so it would have been a complete waste of money to opt for them.

Ok, it is still not an issue as long as they meet at 100% and are close at 20%.

Do you mean the GW5048D-ES? Yes it is NRS-097 certified. Just search for "NRS 097 Approved inverter list" and the CT list will pop up with a table of approved inverters with their report number and certificate number.

The Staubli connectors that come with the panels are about as premium as they get, they stuff that is usually mated to it is usually far from it.
The connectors have a completely different structure than what you get in a typical wall plug - look inside the female and you will see they have a number of spiral or straight contacts made from plated spring material. This arrangement ensures much better contact than the (usually 2) contacts in an AC socket.
I'm pretty sure that's not true, and also the source of many of the problems.

That is the reason i use a 1000v 32 amp dc isolator to test ISC( short the string out in good sunshine) take a current reading compare to specs then leave for 1 hour and the guys feel each mc 4 connetor for bad seating and incorrect crimp connections.( heat) Never use the mc 4 connectors at the end to do this test as you will destroy the connector when you disconnect( huge arc).Below dc isolator i use for this test with leads and mc4 connectors attached to the contacts. All this is done before connecting the strings to the dc combiner.

Most likely because the mating connectors weren't compatible, or badly crimped. This is the biggest risk with poor installations. Ideally all mating connectors should be of the same manufacturer and same series. Rule of thumb is that if it has a red oring, it's not genuine Staubli (most likely what the Canadian solar panels came with) - if it has a black oring it might be. It's worth paying the exorbitant prices for Staubli connectors and proper crimping tools if it means your house won't burn down.

Most likely because the mating connectors weren't compatible, or badly crimped. This is the biggest risk with poor installations. Ideally all mating connectors should be of the same manufacturer and same series. Rule of thumb is that if it has a red oring, it's not genuine Staubli (most likely what the Canadian solar panels came with) - if it has a black oring it might be. It's worth paying the exorbitant prices for Staubli connectors and proper crimping tools if it means your house won't burn down.

Most likely because the mating connectors weren't compatible, or badly crimped. This is the biggest risk with poor installations. Ideally all mating connectors should be of the same manufacturer and same series. Rule of thumb is that if it has a red oring, it's not genuine Staubli (most likely what the Canadian solar panels came with) - if it has a black oring it might be. It's worth paying the exorbitant prices for Staubli connectors and proper crimping tools if it means your house won't burn down.

Most likely because the mating connectors weren't compatible, or badly crimped. This is the biggest risk with poor installations. Ideally all mating connectors should be of the same manufacturer and same series. Rule of thumb is that if it has a red oring, it's not genuine Staubli (most likely what the Canadian solar panels came with) - if it has a black oring it might be. It's worth paying the exorbitant prices for Staubli connectors and proper crimping tools if it means your house won't burn down.

For example, Hager HIC line is great, but just like you said - not really affordable. Not to mention the sheer size of the thing.
There IS a proper way how to create ATS using two contactors, but they have to be mechanically interlocked, not just electrically. You can even buy all the necessary components as a set that's meant for reversing the rotation of 3-phase motors back and forth. But given my poor skills, I am a bit afraid to build it, so I resorted to Chinese crap, backed with some prayers
A proper ATS using mechanically interlocked contactors:
Mechanical interlock:

 

Yeah, please don't install any switch-gear that is not certified to the standards required in your country (or at the very least the equivalent ISO standard if you are willing to do the research and take on the risk.) Even if it is a completely off-grid installation. Something like this can quickly turn into a fire. 
It's also a good idea to check all your terminals annually and tighten them, thermal cycling can cause them to work loose, leading to a situation like this.
On a side note - there are no affordable certified ATS (that I could find) - those that were certified cost about as much as an 8kW NRS097 hybrid inverter. So my suggestion is to rather design your system so that it does not require an ATS. You can use contactors, but not in the same way as you would an ATS. IOW, you cannot use a NC and NO contactor to function as an ATS, since they cannot guarantee interlocking/break before make.

In some cases with some boards with heavy copper fills, I have previously resorted to using a soldering iron from both sides, before trading one for a compressed air gun to blow out the solder. It works really well on stubborn vias, but be prepared for a cleanup.
Having proper equipment is really worth the investment, though!

Technically, you are not allowed to increase the supply - if your eskom supply is 150A, then that is the maximum breaker you may install anywhere in the system. The solar is not allowed to supplement above that limit. (But nobody pays attention to that, so do whatever you want.)

Technically, you are not allowed to increase the supply - if your eskom supply is 150A, then that is the maximum breaker you may install anywhere in the system. The solar is not allowed to supplement above that limit. (But nobody pays attention to that, so do whatever you want.)

Not quite - it's output is the DC bus voltage, which should be around 330V (the exact voltage depends on your AC voltage and some other factors). Apart from that, it's under software control, meaning that the response time is limited. So there exists the possibility that the current might overshoot the capability of the hardware - possibly saturating the inductor and killing the IGBT before the software even knows about it - that is why there is a Isc limit.

Not quite - it's output is the DC bus voltage, which should be around 330V (the exact voltage depends on your AC voltage and some other factors). Apart from that, it's under software control, meaning that the response time is limited. So there exists the possibility that the current might overshoot the capability of the hardware - possibly saturating the inductor and killing the IGBT before the software even knows about it - that is why there is a Isc limit.

Your inverter can only invert 5000W. The MPPTs can do 6500W, but then your batteries have to be taking at least 1500W of charge (the rest going to the grid/backup).

I'll take this with a teaspoon of Sodium Chloride.

Except if the coil is already energized, the contacts closed, and grid fails, you could still be powering the relay coil from the inverter through the contacts. There is a specialized anti-islanding device that is a bit more complicated for this sort of application:
https://www.victronenergy.com/accessories/ziehl-voltage-frequency-sensitive-relay-ufr1001e
Aside from that, inverters that comply to IEC 62109 (or perhaps VDE-AR-N-4105, not sure) and NRS097 should have ample anti-islanding redundancy that you don't need something like this.

This is a supply side issue. According to our grid code the supply should not exceed 253V. What happens here is your supply is already at the upper limit. Then once the inverter starts generating, it lifts the voltage over the limit. This most likely also indicates that your impedance to the grid is not low enough. The inverter should not be able to raise the voltage that much. This can be due to your supply, or installation. Sadly, a different inverter will not solve this issue*, as the problem is with your supply or installation, and any inverter that complies to NRS097 will disconnect and indicate a fault under these circumstances.
*unless you choose  a different grid code, in which case it is not NRS097 compliant anymore and should not be able to get a CoC.

At high-rate discharge, eg 1.5 C, the extraction of lithium ions from one electrode and intercalation to the other is too strong to be efficient. This damages the electrodes’ elasticity. Furthermore high rates increase the battery’s internal resistance. The battery will have to strive to deliver high current and use more power to keep the same voltage level, which will therefore make it age faster. For surge on inverters the 1.5c discharge comes in handy with inductive startup loads that only last a few milliseconds. Constant Charging/ discharging a 5kwh battery at 150A(7200w) will increase the temperature in the cells also speeding up the aging process.
No argument that the Greenrich lfp batteries are good quality but for longevity 0.5c charge/ discharge would be the wise decision. If more power is required rather install more capacity in parallel.

I have measured these and they will increase in temperature 4x faster than Pylontech's 0.5C batteries at the same C-rate of discharge (the greenrich has 4x the internal losses of an equivalent pylontech). I would not use them at a higher rate than 0.8C, preferably 0.5C.
The claim about the cell surface area is useless when it's re-packaged in the same form factor.

From my experiments it looks like pylontech just has better cells. (and for 4 times more losses, you only need double the internal resistance)