Old Goodwe CAN to RS-485 for Pylontech

Hi all.

I started with a job to upgrade batteries on a GOODWE installed in 2016 by someone else. It is a lightgreen unit I have never seen before. The unit has no CAN comms but there are 2x RS-485 ports only. The 1 RS-485 is used for the energy meter and the other one is ment to connect to a battery using a GOODWE EzConverter no matter what comms are used.

I have 3 Q’s

  1. Goodwe do not have any stock of the converter here or in China. Will a general CAN to RS-485 do the job or do I need a dedicated GOODWE product? I see them all over the net.

2.If one can not mannage the CAN to RS-485 convertion can I try use the Pylons under ''users define"? If so, what settings will be good for the new Pylon 3000C models?

3.Lastly, I can not mannage to connect to the Inverter using PV Master so now I wonder if that unit may not have WiFi. If that is the case, how do one comunicate with it?

Any help will be welcome.

I will try to load a pick of the inverter.


Any RS485 should be fine to connect to that port. The issue will be what commands the unit works with over that port. Here there are no standard way with every manufacturer doing how they think best. There are also mutiple CAN interfaces. Some standard and some not.
Good luck :thinking:

Oh dear! :frowning_face:

This should be fine, although… check warranty requirements. If the battery is rated for off-grid use then sometimes it does not matter, but it is also possible that the warranty is void unless you have the CAN-connection installed. I know some Pylontechs are off-grid rated, but I don’t know about the 3000C.

If you do this, I’d use 52.6V float, 53V absorb, and limit charge current to 35A per module. The exact voltages doesn’t matter too much. Just stay far away from 54V (because that is where the battery switches off), but stay above 52.5V (the minimum the battery needs to do any sort of proper balancing).

Edit: For your low battery cut-off you can use something nice and low, like 44V. The battery will protect itself as well, by switching off if any one cell drops too low, so you don’t have to worry about this too much.

Thank you Plonkster. I get the feeling that this will be the way forward. I now have to look at how to communicate with the inverter as I can not connect with PV Master. This I will followup with Goodwe in China.