Daly 100Balance BMS + Vevor Inverter

[reykroona]

Hi,
First off, thanks for this project, I based a lot of what I've done so far on what it can do, and I'm excited to see how this project grows!

I wanted to share a little about what I've found so far because it might be useful for others in the future.

Goal: Charge my new EV at night with a donor Nissan Leaf batteriy that will charge with solar throughout the day. A lot of my decisions were done for budget reasons (for better or worse) so that it's worth the money I'll hopefully save on my electric bill.

Background: I took the battery out of a donor Nissan Leaf and put the batteries into 14s 48v packs and have them in parallel. I currently only have 3, but will build out the rest as it grows. I bought Daly 100Balance 40a BMSs (without RS-485 unfortunately), and the VEVOR Hybrid Solar Inverter, 6000W (which is very inexpensive compared to others). It's not split phase, but since I'm running everything off grid I think that should be ok. I also already have an OpenEVSE charger, so I'll be using Node-RED to decipher the MQTT payloads and turn the charger off when the battery voltage gets to a certain point, as to not hard cut off the inverter or BMSs. I put in some other safety things like listening for alarms and watchdogs to make sure it's still getting data from the BMSs, as well as some debounce features so it won't try to keep charging the car if there is voltage sag.

Communication: I bought a Raspberry Pi 5 with the Waveshare 2ch RS-485 hat, thinking the Daly has a RS-485 port (because the photos on Amazon showed it and there's a port, but you need to make sure you order one with it). So, I bought some UART to RS-485 and connected those to the BMS UART ports and the ran them in daisy chain to the Pi. Then the inverter plugs in to the other port on the Pi.

BMS Issues with BMS-to-Inverter: I discovered a couple things with these BMSs

1. They seem to all communicate on ID 1. So I changed their IDs to 11, 12 & 13 with the PC program (can't do it on the app).
2. They dropped out a lot and would work well solo, but not all together. Initially I found that if I dropped the retry to 0 and the Poll Interval to 0, it would work better. But about one in 3 polls would fail. But I figured over 30 seconds or so it would get all of them a few time.
3. It seems that the 100Balance don't send the Max/Min Charge/Discharge Currents.
4. There's something weird with the Min/Max voltages as well, I had to multiply them by .3 to get accurate voltages. So not sure what's going on there.
5. I'll have to check again, but I think one of the commands was expecting two rounds of responses, but only sending one.

Inverter Issues:

1. The inverter uses Pylon 3.5 protocol (or at least part of it) and expects their US2000 batteries. I tried lots of variations of this and Solar Assistant and couldn't get anything to work. There is very little information online about this, but I found a Ukranian power forum where someone got the PDF with the protocol, I'll upload it here for people if they are looking for it.
2. The inverter sends 8 requests, one about every half second. It's polling for the 61 and 63 CIDs, 4 batteries each. If it replies too slow it drops connection.

Solutions:
Using a lot of AI, I was able to rework some of this code.
For the Daly RS-485 section, I changed it so that it would retry the request instead of just waiting 10 times for the data. This seemed to fix most of my issues with them not responding. I also had it send a default for the min/max currents so that the data would be valid as well as fixing the command that was expecting more data.

For the Inverter, I added/updated the functions for the 61 and 63 CIDs and added functions to build the frames correctly. I also had AI make me a little Python emulator I can upload, it just sends dummy data to the inverter, but it proves that you can in fact connect to it.

I also edited the configurator.jar so that the inverter can update in ms, so I could set it to 250. This seemed to fix my issue with it disconnecting every 30 seconds or so.

Anyways, I forked the repository on my GitHub (https://github.com/reykroona/bms-to-inverter). I'm sure you could integrate some of it if you wanted but I'm not really good enough of a programmer to do it and do a pull request. But hopefully some of it is useful if someone ever wants an update for the 100Balance BMSs or the Vevor Inverter.

That's it for now, hope this helps someone out there, next I need to work on the solar panels.

Rey

Here's the protocols sheets if anyone needs them:
RS485-protocol-pylontech-low-voltage-9600.pdf
Протокол PYLON LFP Vx.1 ukr.pdf

[ai-republic]

Thanks @reykroona! I saw that you created a PR for your changes. I will review them and see if I create a separate binding for the DALY 100balance as the current bindings (CAN & RS485) work correctly with the current implementation for the standard DALY 100Ah CAN/RS485 BMSes.

As for the inverter issues I will also check the changes. I have one question about the inverter communication. I have a user here who also uses the Pylon RS485 protocol but the inverter does not send any requests by itself. Somehow it needs to get a startup request/message to start requesting data from the BMS. Did you have any findings in that?

[reykroona]

I found that either the Hat didn't start sending anything, or the inverter didn't start sending anything until it tried to send a request, so I added a "warm up" for the first 5 seconds where it would send requests. I saw last week you added an auto send request, but I turned that off for mine because I thought it was causing disconnects, but I did that pretty early on in the troubleshooting so it would be interesting to have that back in and see if it works.