Hello frank, pleased to make your acquaintance.
And again thank you for your answer.
All this has been done. And program 5 has been set to PYL.
After reading your info I am left with a bundle of questions...
Now, I assume that I have established this communication because all the cables you mention are there and the Axpert 'knows' the Pylontechs. (unless RS485 is a cable too, which I have and can plug into the Axpert. I have shouted very loudly at the other end of this cable, but the Axpert does not hear me. ??) But how do I get to use the 5% SOC steps then? Where do I find this 'communication (RS485)' and how do I change it from V to SOC?
You already using closed loop communication (via RS485) and setting in program 5 set to PYL. My EG4-6500EX inverter instructions say the following:
Because you've already chosen PYL in your program 5, the programs 12 & 13 should automatically show SOC in percent instead of voltages (if running in "SBU" mode!!
Now this is where I get really interested, but confused at the same time. SolarAssistant does not mention such settings in their info for Axpert Inverters.
- How do you get data from SolarAssistant? Does it connect via WiFi, or does a cable have to be installed? Or worse, does it only work with a raspberry PI? Judging from the site, Solar Assistant does what WatchPower does, with only one thing added: it will control setting 99 and 100 (timers to switch to grid or solar) by SOC rather than Voltage. Other than that I can not see any difference.
Both Axpert Max and EG4-6500EX (and a lot of others) are built by Voltronic and because of that, they are very similar. Search for Voltronic in the SolarAssistant documentation and it will match our inverters.
SolarAssistant runs ONLY exclusively on a Raspberry Pi - by intention to be a robust 24/7 solar monitoring and controlling solution - more like a device instead of just a "program".
You can use WiFi or Ethernet to connect this SolarAssistant "device" to your home network (I'm using WiFi) and the location of the Raspberry Pi has to be close to your inverters/batteries. The inverters are connected via RS232 to the inverters (via USB-to-RS232/RJ435 adapter cables). Optionally you can connect the batteries via RS485 (via USB-to-RS485/RJ45 adapter cables) or RS232 (via USB-to-RS232/RJ435 adapter cables). It depends on which battery model you're using.
Beside the inverter information, SolarAssistant may get the battery information from the inverters also if the inverters are closed loop connected to your battery BMS (like in your case). If the inverters are not closed loop communicating with the batteries, you can attach the batteries directly to SolarAssistant.
- What are 'smart home rules' and how do they control the AC-in contactor?
Because SolarAssistant now has all the inverters and battery data, it could (optionally) send these data via MQTT to other systems for further processing (it's not a requirement - SolarAssistant runs by itself and has also some automation possibilities).
But in case you already have a complete SmartHome system like HomeAssistant or OpenHAB (like me) which are able to communicate via MQTT with other systems, you will have all the power of these SmartHome systems also available for SolarAssistant. e.g. monitoring different values, developing rules based on value changes, etc. etc.
Here are some typical rule examples of a SmartHome system:
- Switch on all lights and sirens if a door or windows contact will be activated (alarm system).
- Switch on specific lights depending on which motion detectors are activated around the house.
- Switch on/off lights depending of daylight values (sunset/sunrise).
- Switch on my garage air conditioner if my inverter temperatures getting too high (I live in the hot Arizona Mohave desert).
- Switch on my AC-in contactor in case my battery voltage (or SOC) will drop below a specific value.
- etc.
To be able to do all this stuff, for sure all your sensors and actors must be connected to your smart home system and to do that, they must be kind of "smart". There are some standard protocols to connect smart devices to SmartHome systems (e.g. Z-Wave, ZigBee, MQTT, etc.).
In my case, the inverters are now "smart" via integration with the help of SolarAssistant and MQTT into my OpenHAB system. The Shelly Plus 1 dry contact relay is "smart" because I flashed it with Tasmota to be a MQTT controllable remote WiFi relay and it's also integrated in my OpenHAB (at the end, the Shelly relay drives my typical 110Amp/120VAC contactor to connect the grid to the AC-in).
Now I can develop rules in OpenHAB which will be triggered if my battery voltage changes to specific values and in this rule I can send commands to the Shelly relay which opens or closes the AC-in contactor.
- Do you have an explanation as to why your Voltage values are so different from mine? (For example, the batteries have been charging all day by the PV panels, the SOC is now @70%, but the voltage is only 50.5V... And thus the grid keeps charging the batteries. As I said, I will probably never get to the minimum of 51V...
I'm not really sure - but as far as I remember the Pylontech batteries only use 15 LFP cells instead of usual 16 to build a whole battery which reduces the battery voltage. So you need to adjust your voltages compared to mine. You need to know the relation of your battery charging voltage chart with it's SOC and also the discharging chart to know very exactly which voltage matches which SOC (it's different for charging and discharging).
This I get. How it gets done 'automatically' is probably with SolarAssistent, or SmartHome. (My house runs on a domotics system called SmartHome (by Carlo Gavazzi), but I suppose you are talking about something entirely different). But you cannot do the same in the other 'direction': to achieve that you need a WiFi relay... Correct? (But then how do you make the dry contact switch?) In any case, voltages of 53 and 52 are out of my league. Even 51V seems unatainable. In which case, the grid would NEVER be disconnected again.
Do you have to do that manually every day? Or can this be achieved "automatically?
I set everything up in a way that it's completely fully automatic.
As of here, it is getting really difficult. I get the 0.1V steps. But you seem to run SolarAssistant (on a PI), this then connects to other software called SmartHome. (Never heard of openHAB) And then you need to reset the system manually on a daily basis. But I could achieve it by learning how to program MQTT code (of which I have never heard either)...
The rules are automatically adjust the values of program 12 depending on inverter mode and battery voltage. As I mentioned OpenHAB is like HomeAssistant, just an open SmartHome system.
But all this is not really required to run a solar system, it just gives you a lot more options to control and optimize everything very accurate.
Pffff, I can see why Axpert is so much cheaper than my other 2 Victron systems. All I need to do there is take my phone, open the App and change whatever I want.
I probably (and hopefully) wrongly interpreted or misunderstood quite a few things in your answer. But it seems like a real daunting task to get where I want to be.
PS: fancy a 2 or 3 week holiday in Spain? You are welcome to my house. All yours and free! Albeit that you might run a bit short of electricity. But surely you would be able to manage that...
Thanks for the invitation
In case I would ever be in Spain I will let you know
Hope to read you soon.
Greetings, Kurt