Solis Hybrid inverter with DIY battery

So, phenomenal progress this evening. I got my wee UART to CAN bus adapter, (about £5 on amazon), and I had a few ESP32 boards lying around. So I used the git repo in the second post on this thread and built a variant of what's in the repo diagrams, no display, no digital isolator (that the impatience in me). A few hours to get the sketch to compile, there's a particular version of the Daly UART lib that's needed. Guru Meditations (crashes) all over the place, but now I'm finally getting places.

This is with the battery set to User Defined, and it's successfully reading the SoC of the BMS though the CAN bus interface and displaying it on the inverter! It's also showing "CAN OK".

It's not doing much else at this stage, but I think this is a huge milestone for me, and I think I'm on the right road to getting my battery working with the Solis inverter, finally. :)

At this stage I've got my canbus bridge emulating user-defined, aobo (using SMA protocol), and Pylontech (I did the changes to give the correct name and the metrics in the right places according to the pylontech doc above), and I'm still not getting current pulled from the battery. I've verified the battery with a resistive load and can easy pull 10A from the BMS, app shows info fine. Just not working with the Solis no matter what I try.

Here's a quick update now that I have the battery working. I was able to get the battery charging at night between 2-4am (1/4 price night rate), as well as topping up the immersion without interrupting each other. All pulled from the grid, then at 4am switched back to powering the house from the battery. :)

On the charge slope, I believe that's the charge curve of the battery, CVCC, so once it gets to the target voltage, it ramps down the current till it gets to 0.5c rate, at which point it's charged. On my tariff, 2am to 4am is the 1/4 price rate (7.5c/kWh). Anything outside that is 1/2 price rate (15c/kWh till 8am). You might be right on moving the Eddi boost time. I'll try boosting immersion closer to use time, but each unit later in the night costs double, so I'd only want to put it on for half the time, and see if it ends up at the same temperature. I'll give it a go. Yes, Eddi for the immersion.

Not so far, decent showers in the morning, but I'd estimate I'm only getting about 3-4kWh of energy into the cylinder. I have 4 temp sensors attached to it, and the bottom never gets much about 20degC, where the top sensor shows about 63degC. Thinking of longer immersion element or getting a willis immersion fitted. I've been told that I could get much more energy into the cylinder that way, up around 6kWh, so a lot more hot water that way. Current setup is not circulating water at all, so it's all sitting at the top. The average of all the sensors drops from about 44devC to 42degC between 4am and 8am.

Good suggestion, I'll look into a destratification pump as well. Eddi wired into both sink and bath elements, it's definitely set to bath, the sink setting heats far less. My problem in controlling the pump from the eddi is that it's downstairs in the utility, whereas the cylinder is upstairs, and I've no easy way of running a cable to the pump from the Eddi.