Pylon US3000C, SMA and Eltek Can Bus

Tinbum
Posts: 1118
Joined: Mon May 31, 2021 9:55 pm

Re: Pylon US3000C, SMA and Eltek Can Bus

#11

Post by Tinbum »

Latest iteration;


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85no 58mm solar thermal tubes, 28.5Kw PV, 3x Sunny Island 5048, 2795 Ah (135kWh) (c20) Rolls batteries 48v, 8kWh Growatt storage, 22 x US3000C Pylontech, Sofar ME3000's, Brosley wood burner and 250lt DHW
Tinbum
Posts: 1118
Joined: Mon May 31, 2021 9:55 pm

Re: Pylon US3000C, SMA and Eltek Can Bus

#12

Post by Tinbum »

It's been quite some time since I wrote an update to this thread so here it is.

Unfortunately the Long Covid is still physically limiting my life greatly but, thankfully, I've not had the brain fog and my mental ability is ok but i'm still limited by my available energy and weird vision. So all the updates are still on the bench until I can physically install them.

I have expanded and now also have 3 Sofar ME3000SP's in the system so I needed think about how to control them. The Teensy only had 3 available CAN ports so I had to expand. The easiest way was to add another Teensy to link to the 3 Sofars. This had to be connected to the original Teensy so this is done over Serial interface.

The greatest problem with having so many inverters and chargers is potentially exceeding the Pylontech max charge current. The SMA inverter is great because it actually transmits its charging current over the CAN network, as do the Elteks. This is as measured by the inverter not the battery. The Sofars do also measure this current but they just enter 0x00 in the CAN message they transmit. I've tried to get Sofar to do a firmware update to populate the CAN message with the actual value but no joy. The Sofar does however transmit the value over RS485 so I've had to resort to using a Raspberry Pi and then transmitting the values over MQQT for the Teesny to receive. These values are then used to calculate exactly what charge current headroom is still available to each inverter.

The control system now has the following;
A reduced Charging voltage setting. (Also reverts to Pylontech rate once a week and resets on 100% SOC).
A balanced charge from the Elteks (from the grid) that matches demand from the batteries if they are low.
A manually set constant voltage charge, either 52.5v or 53v, to ensure full cell balances.
An automatic charge from the Elteks (from the grid at anytime) when the SOC is very low.
Eltek battery charging during low rate grid, controlled by the next days forecast (Solcast) The current is calculated so the whole set time period is used. It also automatically allows for if the DHW is being heated during the low rate period. (Also reverts to 100% SOC once a week and resets on 100% SOC).

All the above still has all the Pylontech battery protection so the battery is still in charge.


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85no 58mm solar thermal tubes, 28.5Kw PV, 3x Sunny Island 5048, 2795 Ah (135kWh) (c20) Rolls batteries 48v, 8kWh Growatt storage, 22 x US3000C Pylontech, Sofar ME3000's, Brosley wood burner and 250lt DHW
Kommando
Posts: 83
Joined: Sat Aug 12, 2023 10:38 am

Re: Pylon US3000C, SMA and Eltek Can Bus

#13

Post by Kommando »

I have just obtained an old SI5048, currently just planning to use it to charge some lead acid batteries using some off grid panels so that in the event of a power cut I have some backup. I ran the house overnight last night off the batteries and the sun recharged them today, did not try any heavy loads.

Its good to see I can use the SI6048U firmware to upgrade to Lithium with BMS later on when the lead's call it a day so thanks for the info.

I am going to try and communicate with the SI5048 using a RS485 piggyback connected to a Modbus/TCP converter when I get the time.
Kommando
Posts: 83
Joined: Sat Aug 12, 2023 10:38 am

Re: Pylon US3000C, SMA and Eltek Can Bus

#14

Post by Kommando »

The Modbus did not work as the SI is using SMAnet not Modbus, but switching back to serial instead of Modbus I can use a virtual comport on a PC to remotely connect Sunny Data Control. This gives me the data and also the ability to adjust parameters such as charging voltages on the fly.

If I setup Island Manager off Github it will translate the SMAnet into an SQL database, then using Mango Scada on the same PI I can then use the database as a data source to populate a Modbus publisher ie slave to emulate a later SI with modbus and then send the data to my Solar-Log which all my Sunny Boys are connected to.
Tinbum
Posts: 1118
Joined: Mon May 31, 2021 9:55 pm

Re: Pylon US3000C, SMA and Eltek Can Bus

#15

Post by Tinbum »

I've not done much with Modbus and use a Sunny Webbox to communicate and log with my Sunny Islands.

I find CAN much easier to use but do wish it would be standardised. I've just purchase a Growatt battery and written a sketch to decipher its CAN communication and it's so different to the Pylontech, SMA or Struder CAN. None of the ID's are the same, though it does give loads more information which is good.
85no 58mm solar thermal tubes, 28.5Kw PV, 3x Sunny Island 5048, 2795 Ah (135kWh) (c20) Rolls batteries 48v, 8kWh Growatt storage, 22 x US3000C Pylontech, Sofar ME3000's, Brosley wood burner and 250lt DHW
Kommando
Posts: 83
Joined: Sat Aug 12, 2023 10:38 am

Re: Pylon US3000C, SMA and Eltek Can Bus

#16

Post by Kommando »

I will be trying canbus too, I have Venus OS loaded on a pi, just need to install the SI driver off GitHub. I do not expect much sense to come out of the SI as I have a pre Lithium firmware on the SI. I want to know how to downgrade firmware on the SI first before loading the SI6048US firmware, it can be done as I have a Training presentation detailing the feature but not how it's done.
Tinbum
Posts: 1118
Joined: Mon May 31, 2021 9:55 pm

Re: Pylon US3000C, SMA and Eltek Can Bus

#17

Post by Tinbum »

Kommando wrote: Sat Sep 09, 2023 8:03 pm it can be done as I have a Training presentation detailing the feature but not how it's done.
I'm not sure as I've never tried it. I run mine in 3 phase and i know if the master is running newer firmware it updates the slaves and I think the opposite is true.
85no 58mm solar thermal tubes, 28.5Kw PV, 3x Sunny Island 5048, 2795 Ah (135kWh) (c20) Rolls batteries 48v, 8kWh Growatt storage, 22 x US3000C Pylontech, Sofar ME3000's, Brosley wood burner and 250lt DHW
Kommando
Posts: 83
Joined: Sat Aug 12, 2023 10:38 am

Re: Pylon US3000C, SMA and Eltek Can Bus

#18

Post by Kommando »

This is the training manual link, it confirms downgrading the master firmware will cascade down to the slaves as well as per upgrades.

https://www.energistar.com/documentatio ... 160855.pdf
Tinbum
Posts: 1118
Joined: Mon May 31, 2021 9:55 pm

Re: Pylon US3000C, SMA and Eltek Can Bus

#19

Post by Tinbum »

It may just be a case of loading the older firmware to the sd card.
85no 58mm solar thermal tubes, 28.5Kw PV, 3x Sunny Island 5048, 2795 Ah (135kWh) (c20) Rolls batteries 48v, 8kWh Growatt storage, 22 x US3000C Pylontech, Sofar ME3000's, Brosley wood burner and 250lt DHW
Kommando
Posts: 83
Joined: Sat Aug 12, 2023 10:38 am

Re: Pylon US3000C, SMA and Eltek Can Bus

#20

Post by Kommando »

I suspect it could be that simple or just pressing escape whilst inserting the SD card with the old firmware loaded.
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