I've been using Wonder Watt for a few weeks, but this morning, for reasons unknown, smart charging didn't happen as it usually does. As I don't want my charging today to be interrupted if Wonder Watt wakes up again, I've now broken the connection in my settings by specifying a wrong username and password.
Reluctantly, I'm coming to the conclusion that at least during the winter months Wonder Watt isn't really going to be useful. The amount by which it wants to charge seems to be very dependent on where the battery is just before the charging starts, not just where it needs to be at the end based on the forecast, and sadly the forecasts aren't proving at all accurate at the moment. As I'm on Octopus Cosy and have two possible charging windows and my usage before the afternoon one is likely to leave plenty of room for the battery to charge whatever the weather between 7am and 1pm I'm thinking I might just as well charge at a rate of about 50% during both windows, and that's likely to get me to close to 100%battery by 4pm, which is where I want to be.
For the record here are Wonder Watt's predictions versus actual production since the fix was rolled out:
2023-10-27 4.7 2.9
2023-10-26 6.5 3.2
2023-10-25 9.8 7.9
2023-10-24 8.5 4.0
2023-10-20 2.5 0.7
2023-10-19 5.2 5.4
2023-10-18 4.5 5.1
2023-10-17 8.8 13.5
In each case the first figure is the prediction, the second the actual production. Three days are missing as I was away, so switched smart charging off during that time.
One problem may be that I'm not really able to describe my system accurately. The panels are in between south and south west (around 172 degrees), and I have twelve 300w panels but the inverter is limited to 3kW.
Wonder Watt might be more useful to me if I had more battery capacity, but during the winter my daily usage is currently always going to exceed my storage capacity since I have a heat pump. In the summer, when my usage is likely to be a lot less it might be more useful, but in all likelihood I'll rarely need to charge at all then.
