Technical Support

I’ve had a few weeks of using the 12kW 3-phase inverter and 4x BYD 5.12 batteries. I’ve had an overall positive experience, but thought it might be useful for others to share some observations and solutions to issues I've encountered, as well as some ideas for future features.

Feature ideas

1. On the Overview Power Flow on the app it would be great to split out Grid/Load/Aux, so it’s easier to see when the Aux port is active and using power.

2. Aux control integrated into the System Mode:

   1. So for example it can be used to selectively drain the batteries. If it's going to be a high production day, and in the morning there is charge remaining in the battery, i'd love to schedule this for use by the immersion heater rather than using the gas boiler.

   2. Alternatively I may want the Aux load rules only to be applied at certain times. I have an EV charger that uses its own CT to look for export to the grid, it currently competes with the immersion heater, and I have to manually switch the Aux load setting to “Gen Input” so the immersion heater doesn't kick in.

3. The App should auto refresh, as it is often out of touch with what is happening right now. I know from recent videos Sunsynk are moving hosts to make the update more regular, it would be great if it could get closer to mirroring the flow diagram on the inverter.

4. The income information needs to be able to accept fractions of a penny, my Intelligent Octopus night tariff is 7.5p, the app only lets you put 7p or 8p.

5. It would be great to make an intelligent system mode that uses tomorrow's forecast to change settings automatically. For example on a sunny day it might drain the battery overnight as low as possible to make space, as it will charge the next day, while on a grey day with minimal production it might use cheap overnight electricity to charge the batteries up so it can discharge during the day.

6. App notifications, it would be great if the app could drop you a notification for certain things, like the Aux load switching on, the batteries being full/empty, import from the grid over a certain amount etc.

Observations

1. The instructions around the CT Clamps aren't clear, the instructions that were sent with the inverter show the arrow on the CT Clamp going one way vs the latest version of the instructions online which shows it the other way.

2. The system isn’t very accurate at measuring import and export from the grid, and is often a few kWh different from my meter.

3. The inverter is much noisier and puts out a lot more heat than I was expecting. I would have considered installing it elsewhere if I had realised the noise it would make when it ramps up.

4. The system always draws something from the grid even when set to export excess, and its reaction time means just normal usage results in about 1.5kWh of grid usage a day, even if you’ve generated enough energy from solar to be off-grid. So given that Octopus offers us export payments (4.5p) at a rate 10x less than import costs (40.75p) and you have to pay a standing daily charge (41.39p), you would have to export 22.8kWh a day to get your bill to £0!

5. The BYD 5.12 batteries use Surlok Amphenol 5.7mm connectors, that can accept 25mm DC cable and are rated for 120A, the batteries do not come with any connectors, or cables. They are compatible with Pylontech battery link cables, which can be found easily and cheaply online. This would have been useful to know before they arrived, I couldn't find this information anywhere.

6. Buying the Sunsynk kit in the UK was a real mission, there are very few suppliers, Sunsynk won’t sell to customers directly and it took quite a while for me to find someone at Edmundsons Electrical that had heard of or actually knew they sold Sunsynk kit.

7. The explanation for the earth neutral bond in the instructions is poor, and you have to watch some of Keiths videos to try and piece together the reasons for this. There are also contractions in the instructions where it shows a diagram of the PE on the Load connection being connected to the Neutral via a contactor, but in another diagram it says “Do not connect this terminal when the neutral wire and PE wire are connected together”. As the reason for this connection isn’t clear, it's hard to know which instruction to follow.

8. It would be good to have more model settings, showing a range of scenarios and the optimal settings and the reasons why, I get that the system is a “swiss army knife”, but it took a lot of research and many hours of watching videos and trial and error to get it all running with what is probably quite a standard setup in the UK (potentially not in South Africa)

9. There is very little information on how to get the system working well with an EV charger, Sunsynk tech support said they’ve not got many EV’s in South Africa so had no advice to offer. I’ve ended up using a 22kW Zappi with an export margin that works quite well, but it still requires some manual settings changes to get the best out of it, and it seems like a 4 way fight between the charger, the PV production, the battery drain and the Aux output.

Anyway, I hope the above is useful, I think the product has huge potential, so I just wanted to offer my feedback, which I hope you can use to improve these minor gripes for others.