mocodo

Awesome feedback, thanks @Sidewinder
Looks like my best option is to bite the bullet and get a professional to sort it out.
Can't beleive I ever got a CoC for this system. Must have been a back handed deal with the installer.

@mocodoLet me give this a bit of a shot....but just remember, treat a comments, not as gospel.
I'm not an Electrician, just an engineer with a bit of OCD, and these are some thing you may need to pay attention to:
1) Split AC & DC ...shouldn't run in the same conduit.
2) Conduit / trunking for DC should preferably be made of metal.
3) I believe from end last year, new SANS regulation specifies even split conduit for PV wiring. TBC.
4) Labelling....lots of it. I see no labelling (unless it is on the Inverter cover), but even inside the new DB's, every item needs to be labelled. The next guy that owns/going to work on it doesn't need to figure out what is where.
5) Warning Signs..Lot's of it, especially on the other (main & sub) DB's in the house.
6) You didn't specify if you are adding a master battery or just adding another slave. If slave, add a disconnect for that battery, and a master disconnect for all batteries. Yes it's a schlepp, but it does make maintenance easier when the time comes (much later). Alternative, you need to ensure that the fuse in the current disconnect is upgraded to handle the increase amperage. (only for adding a slave battery)
General:
1) If possible, get the comms cable sorted between Inverter and battery. Just make life a bit easier with knowing a bit more of what is going on your system.
2) As already mentioned, Earth/Neutral bond, if applicable to your grid supplier.
3) What's with the yellow & blue wires going to the Aux port? Try and keep all types of AC wiring the same. Running out of Red wire is a lame excuse.
4) The wires to the load port looks very thin to me. You should try and route the 3 AC port directly down to the trunking, one set of wires in each flex conduit. Try and find another way to route your CT coil. Maybe rather use one of the empty ports behind the PV ones. I used one of the 3 comms ports (behind each other) next to the big battery port.
5) The plug for the Prepaid. Where is the RCD and CB for that.?
6) If you Inverter is going to work very hard (as most 5kW's do)...then make provision for fans, either at the bottom or on top to push/pull the hot air out.
7) In Change Over DB: From rhs. in position 3 & 4. Look like the have a LED illuminated of sorts. If it is the Grid and Inverter "Live" indicators, then good.
8) Same for position 3 & 4 from lhs, those looks like type 2 SPD's. Good if so. (may just be a reflection, like on your PV DB).

Personal 2c' worth. Just perusing the spec sheets for both, the key differences are in performance (charge/discharge Amps), and then in lifespan (cycle life and warranty).
Choose the Deye if performance is non-negotiable. It's a 1C charge and 1.2C discharge, normally-rated 230A discharge and peak up to 280A. The Dyness is a 0.5C battery with 140A normal discharge rate, and 200A peak discharge. Choose the Deye if you want to go off-grid, and if you often need/intend to use the full 8kW rated power of the inverter without a fallback.
The Deye is however just rated for 6000 cycles with a 5-year warranty, extendable to up to 10 years, but I'm guessing that would cost extra. There the Dyness is better on paper with unlimited number of cycles and a 10-year cycle life, but read the fine print of how it's tested at 0.2C charging and discharging. Choose the Dyness if you're staying on the grid and peak power can be supported from the grid. Choose Dyness if you will be doing regular deep discharges, like charging electric vehicles, running aircons or geysers, or feeding power to the grid, and if your household demand seldom exceeds 6kW to 7 kW.

@mocodo ,
The answer is as always: It depends on your needs!
Owning a very expensive Inverter & even more expensive battery should warrant a decent monitoring system for each component.
Manufactures' efforts (Apps) are basic at best.
Solar Assistant (SA) goes a long way, but from what I can see, both Dyness & Deye batteries mentioned cannot be monitored with SA. If Dyness is mentioned specifically:
Connecting a Dyness / Mecer battery
If an inverter is already reading the Dyness battery, then SolarAssistant can not read the battery at the same time. The battery unfortunetely doesn't support being read from multiple devices at the same time. Set SolarAssistant to "Use inverter values".
This is because once you set up the battery for CAN (to inverter) via dip switches, the RS485 port can only be used a Link port to slave batteries.
Would be nice if some clever ouks can find a way to "fix" this shortcoming.
The Deye battery has a similar port layout to the Dyness (1 x CAN & 2 x RS485), and the Deye battery is not yet mentioned in the SA documentation. Feel free to update this, if anyone know more.
Even so, SA's lack of flexibility and crucial battery information e.g. cell voltages, does not give one the info to know what exactly goes on in a battery, specially during a 24h "charge & discharge" cycle, never mind over 10 years, as these batteries are supposed to last till then. SOH is another metric that is missing in SA.
So, in conclusion, if you never intend to know what goes on in your battery, any of them will do, get the one with the most "bang for buck".
Else get something that you know one will be able to monitor (look for an RS232 port or and additional RS485 port)

Just updated another batch of batteries. There were 3 different types:
Original US3000 US3000C with the older chip US3000C with the new chip Everything went okay, here's the final update window for each type:

Original US3000, named s US3000A in the software:
US3000C with the older chip:

US3000C with the new chip (as identified by E2 or C3 in the serial number):

 

***DISCLAIMER: Use at you own risk. You may brick and/or damage your batteries
How to upgrade firmware of the Pylontech batteries
If it works okay, do not touch it! If it does not work okay, contact your dealer. If your dealer is not helpful, contact Pylontech support. If Pylontech support is not answering, then you can try to upgrade the firmware. Connect laptop PC to the Pylontech battery:
1) First, you'll need to make (or purchase) a serial cable in order to connect a laptop to CONSOLE port of the battery.
Older models of Pylontech batteries are using RJ-11, while newer models are equipped with RJ-45.

Wiring on the right is suitable for all the new models, including US3000C, US5000C, Force H1 and Force H2:

2) A lot of people are struggling with making a working cable, because in some versions of Pylontech user-manual there's a missing information on the GND pin for the RJ-45 console port. Other people are unable to connect since they swapped TX and RX. So, here's the actual pinout of console port for RJ-11 and RJ-45:

3) Grab a Windows laptop PC equipped with a physical DB9 serial port and connect it to the battery stack via the cable above. As an alternative, you can use cheap USB-to-SERIAL converter, for example FTDI-based.
WARNING: Console port is RS232, with positive and negative voltage levels. Therefore, you have to use true RS232 serial-port interface, NOT UART 3.3 or 5V!
4) Download and unpack Pylontech_Tools.zip from the link bellow.
The password for the ZIP file is: Youda
5) Start the BatteryView software:
For batteries with a very old firmware, BatteryView 2 works the best. For new batteries, use BatteryView 3.0.28 or newer. Select the respective COM port and use 115200 baud-rate 6) Now you can perform diagnostic tasks, or update battery's firmware.

Updating Pylontech firmware:
1) When updating firmware, the best is to power-down whole stack, remove all the LINK cables between the batteries and then turning-on just one battery at a time and perform the FW upgrade on it. Then repeat the process for the next battery. Updating batteries while online in a stack works too, but you will get alarms and red lights.
2) There are several models of Pylontech batteries and the firmware is INCOMPATIBLE between most of them:
If you flash a wrong FW in the battery you will brick it. FW numbering is INCONSISTENT between the models. Fox example: For an old battery with certain PCB the FW2.4 might be the most-recent, while for a new battery with a different PCB and chipset the most-recent version would be FW1.9. In other words - higher number does not automatically mean that the firmware is newer, nor better! 3) If possible, it's preferred to update FW via BatteryView 3.0.28 while using following rules:
For updating US2000C, US3000C and US5000 select the whole ZIP file that includes two BIN packages inside and perform update. The BW3.0.28 will be able to pick right BIN file inside the ZIP package automatically. DO NOT select BIN package manually. When updating US2000 and US3000 then you must select the correct BIN file manually, for a shame. 4) Due to the silicon chip shortage Pylontech changed the BMS chip for some of the produced batteries. Therefore, for some models there are two different firmware branches. One for the original chip and the other for the new chip. Luckily, when upgrading FW via the ZIP method desribed above, the BW3.0.28 will choose the correct branch (BIN file) automatically.
 

5) This list indicates firmware version suitable for the each model and what file to flash:

Model: US2000plus
FW: V2.9
FLASH: us2000b_v2.9_Crc.bin
Model: US2000plus95
FW: V3.4
FLASH: us2000B_Plus_V3.4_Crc.bin
Model: US3000
FW: V3.4
FLASH: us3000a_V3.4_Crc.bin
Model: US2000C (original chip)
FW: V2.8
FLASH: NT1.7+2.8.zip
Model: US3000C (original chip)
FW: V2.8
FLASH: NT1.7+2.8.zip
Model: US2000C (new chip)
FW: V1.7
FLASH: NT1.7+2.8.zip
Model: US3000C (new chip)
FW: V1.7
FLASH: NT1.7+2.8.zip
Model: US5000 (original chip)
FW: V1.3
FLASH: US5000 ST+NT 1.3.zip
Model: US5000 (new chip)
FW: V1.3
FLASH: US5000 ST+NT 1.3.zip
 
6) If you have a bricked battery, you can use Pylontech Upgrade Tool V1.0.9 from the Pylontech_Tools.zip to recover it via flashing a correct firmware. The process is as follows:
Connect the debug cable to this software and the battery (attention: at this time please do not switch the battery on), then 1. open the software, click Immediate Update. 2. Click Connect. 3. Click Browse to select the correct firmware. 4. Then click Program and switch on the battery by hard switch and the red soft start button immediately. This will bring the battery back to normal. 7) When updating firmware, it's the best to turn-off all the batteries in the stack and remove all the LINK cables.
Then power-on a single battery and perform FW update on it.
Repeat for the remaining batteries in the stack.
Reconnect all the LINK cables and start the stack as normal.
Although it is possible to perform FW update while the battery is running in the stack, you will get alarms and red lights when you'll do it that way.

8 ) Firmware packages mentioned above are packed in this archive:
Download and unpack the ZIP budle from the link bellow.
The password for the ZIP file is: Youda
 
Youda

Epic! Thanks @mocodo. Mine was close to the truth then.

Hi Scubadude
See attached. Hope this helps.
Best Regards
2x Shoto Battery Setup Diagram.pdf

On my Deye 5kw inverter I am using the following Time of Use settings to run the house on battery from 8pm until sunrise and then PV from sunrise onwards.

Mine do too when I am drawing a higher load. I'm pretty sure this is completely normal and no cause for concern

@mocodo, the lithium icon should be selected. 

Thanks "Sidewinder". My research was in-line with your suggestion.
The installers wiring is way off. 

Let me give this a shot!!
First, setup Battery P1 as master thus A = 10000000
then Battery P2 is slave, thus I = 01000000
(or as instructed by the manual)
 
Can cable (supplied with Inv): Q - B
Next ordinary LAN cable C - L
Next 2 interlinking DC (35mm2 - to handle >50A):
F - N (for +)
G - O (for -)
DC supply to Inverter (70mm2 - to handle >100A)
Note: Both pairs of cables to be the same length
(For +) S - E (and via 200A fused breaker a la Keto or Jean Muller)
(For -) R - P (and via 200A fused breaker a la Keto or Jean Muller)
Note: Do not connect + & - to the same battery, else one battery will always work harder than the other
Optional for monitoring (if you don't have the new dongle - not the Wifi one): The SunSync support is, not sure if the Deye does, seeing they are "brothers"
From RS485 to RPi with RS485 to USB cable
From Rs485 port D on Battery P1 to RPi with RS485 to USB cable (also optional, else you can use the inverter values)
This obviously requires a RPi (3B+ or higher) with good USB PSU
solar-assistant software.
Enjoy