Niel

We have two Pylontech 3000's connected to the Goodwe. The Pylontech provides SOC, charge and discharge settings to the Goodwe and I think if that is the case, you're probably not limited on the number of batteries. One battery is the primary battery which manages the rest and provides the info the to Goodwe. As far as I know, one battery can manage 7 others, i.e. 8 in total. When I installed these last year, the 3000 wasn't available on the app and I left it on default setting. As long as the two communicate, there's no problem. In fact, I suspect the batteries are so intelligent, they will limit the charge and SOC by themselves, even if not communicating with the Goodwe.

Be warned, I am very new to this and may need a lot of hand holding... I'm busy building a home automation system using Openhab on a Raspberry Pi. One of the rules I want to incorporate is switching the pool pump on or off depending on the SOC and total load readings from the Goodwe. I can get these from the app when I'm on the home wifi so it should be possible for OH to ask for the information but I can't seem to find any information on how to do this. I found some guidance on pulling this from the SEMS portal but I'm concerned about delays. I want the pool pump to switch off as soon as total draw reaches 4kW or higher. Has anyone tried something like this or know how to go about it? Maybe someone has hacked the app? Thanks

Are the Pylontech's communicating with the Goodwe? If so, I don't think you'll need to do anything. The batteries tell the Goodwe what the maximum draw and charge current is. Even if they don't communicate, the batteries will limit the charge and discharge current. I'm not sure changing the type/ number of battery actually have any impact. I'm still on a "self-defined" battery. Just FYI, my understanding is that the new battery should be the master, not one of the older ones.

Glad to hear it's working. It seems that is the way things go with Goodwe. There are (stressful) hiccups but in the end every works. Strangely enough, US3000 is still not available on my PV Master app.

These guys from Goodwe has been very helpful in the past: Luke Zhou <[email protected]>,Oliver Shen <[email protected]>

I've done firmware upgrades a few times in the past, some successful, others basically turned the inverter into a blue doorstop. But Goodwe's support via email has been very good and they really keep trying to help until the problem is solved. The Ezconverter solved our battery communication problem and everything is working fine. I still have the battery as "self-defined" as the US3000 is not an option but ultimately I don't think it really matters. The Pylontech communicates it's SoC and charge/discharge capacity to the Goodwe and that is really all that is really important. As far as I know, the SN 9 models are the newer "ARM" models which should be able to communicate directly with the Pylontech. If not, I'd suggest a firmware update. Failing that an EzConverter. I don't think a US2000 will communicate with the Goodwe any easier than the US3000.

I'll be first to admit that I'm a desk jockey and not an electrician but 4.5 years with our PV system have given me some experience. I understand the CoCT rule of 25% but for the life of me can't figure out the reason for the rule (by applying my possibly limited common sense). To limit the impact on the grid if everyone switch from inverter to grid at the same time makes sense from a supply stability point of view but then why the 25% limit? Why not a fixed 3.5kW limit? Take our set-up as an example. Our supply is 60A i.e. more than 13kW. In order to register our 4.6kW inverter as grid-tied, we need to upgrade supply to 80A. How on earth will that make any difference? The maximum we can move from inverter to grid is 4.6kW. What am I missing here?

Interesting. Fortunately our rains can take care of that.

Is SegenSolar no longer involved?

It's almost a week and everything seems to be working fine. It is however interesting to see how the BMS manages the batteries. When the SoC is under 50% (approx), the charge current is limited to 29A (that is for both US3000's). As the SoC increases, this increases to the max of 76A. I'm sure this is to prolong the battery life, probably charging too quickly when depleted causes damage/ wear. It does however mean that they don't charge at full capacity in the morning and significantly quicker in the afternoon. So if you have a NE and NW facing roof and plan to use Pylontech's, place more panels on the NW and less on the NE. And/ or move some more load to the morning and less to the afternoon.

Send me your email address and I'll send you some documents and photos.

And I finally got it to work. It turns out the little switches on the Ezconverter (0 to 5) was incorrect. The communication is working and I see the charge/ discharge current limit was updated. The battery is still set up as "self-defined" Li ion. I'm not sure what to change this to as the US3000 is given as an option and I might just leave it as is for the time being. A thank you to Segen, they were very helpful. If anyone wants more info, I now have some experience on the Ezconverter!

Interesting, I also find that the lights on the Pylontechs don't correspond to what the PV Master tells me and I assumed that was because the Goodwe is trying to estimate the SoC. It seems that may not be the case. I have a question on the SoC lights on the Pylontechs. Does 0/6 lights imply it's reached the 20% SoC limit or has the batteries run down to zero SoC? In other words, do the lights refer to the 3552 Wh nominal capacity or the 3200 usable capacity? At the moment I seem to get about 5kWh out of the two US3000's which is much less than I was hoping for. While a local expert would be nice, Luke at Goodwe have been quite helpful in the past: [email protected]

Thanks, that helps. At least I know it is possible (albeit with a more modern Goodwe). Regarding back-up mode, I understand this to mean that the batteries are not cycled but kept fully charged for mains outages only. Our Goodwe works quite well under the "self-use first" mode but does not seem to know the SoC of the batteries which means it's not efficient.

So I got the cables and did the installation according to the Pylontech and Goodwe manuals I could find, trying both the CAN and RS485 methods. No luck. What is unexpected is that neither the inverter nor batteries lights go on which I take to mean that the Ezconverter is not communicating with the batteries or the inverter. I would think that at least comms with the inverter should be possible as they are both Goodwe. Has anyone here actually got a Goodwe inverter and Pylontech batteries communicating? I starting to wonder whether it is actually even possible.

Thanks, yes. That's how I understood it as well. I appreciate the confirmation. Slide 35 is my source: https://portal.segensolar.co.za/reseller/docs/GoodWePresentationUpdated.pdf

So I received the Ezconverter today. No cables. No instructions. Not very impressed at the moment. I think I know what to do after doing some online searching and looking at the Pylontech manual. From the Pylontech to the Ezconverter seems simple enough: identify pins 2, 4 and 5 and connect them to the 3 CAN pins on the Ezconverter. The connection between the Goodwe and the Ezconverter is not that straight forward. I looks like a regular network cable connection but it may not be that straightforward. It looks like both ends need to be T568B, whatever that means. I have the wires' colour-coding from a diagram so will check that and hope for the best.

Please keep me updated. It will be very concerning if the Goodwe's don't read a correct SoC.

I'm not sure at all. Goodwe in China said I have a non-ARM Goodwe while the newer models are ARM. They made it sound like I need the Ezconverter because it's an older Goodwe. From discussions with Segen, earlier models did not ship with the Ezconverter and they later included this in the package. This MIGHT be what Goodwe China meant, I'm not sure. It might be worthwhile getting your hands on an Ezconverter and see what happens (or maybe wait and see if it solved my problem first).

We have the ES inverter. When I started talking to the guys in China, they initially said the firmware upgrade (and latest app version) will do the trick but when I gave the serial number of the Goodwe, they said I require the Ezconverter to accommodate communication. What happens when you select a Pylontech 2000 battery? Does the inverter and Pylontech communicate with each other? If so, do you use the Ezconverter?

An update: Segen is waiting for three Ezconverters to reach our shores, one of which is allocated to me. From what I gather, these weren't included in the package for earlier Goodwe's but now comes standard with the Goodwe. But if you don't have one, even with a recent Goodwe model, the Pylontech's won't communicate with the inverter. I don't understand where the ARM/ non-ARM aspect comes in. And I'm pretty sure it's impossible to get the most out of the batteries if they don't communicate. The SoC that the Goodwe calculates is way off compared to the lights on the Pylontech's. It quickly calculates 20% SoC and stop using battery power while the Pylontechs appear to be more than 70% charged. So without the Ezconverter, you're pretty much buggered.

I agree and our solar heater works beautifully 6 to 8 months of the year. But I'm curious about your comment about CoCT limiting solar panels. As far as I'm aware, they limit inverter generation capacity (which includes PV panels and batteries), not PV panel capacity? Am I missing something?

We have a solar collector as well. At worst we need to heat from about 20'C to 47'C. Three hours should be enough. The second geyser is for guests only and not often used. So I think it should work. The problem is finding the 1 kW element.

This is very interesting as one can see the impact of the geysers. It seems the solar power is supplemented with grid power when they come on. We have something very similar happening except it uses battery power, not grid. This effectively results in additional cycling of the batteries. I want to investigate the possibility of replacing the 2 kW geyser elements with 1 kW. It will take longer to heat up but I have enough time, not enough PV power. Has anyone tried this before?

It seems the Goodwe Ezconverter is tough to get hold of. Probably with the upgrade of the Goodwe from non-ARM to ARM (whatever that means), the Ezconverter is no longer required and no longer produced. Local suppliers can't seem to find stock. I'm talking to Goodwe China to find out if they can send me one. Of course, if anyone has one lying around, I'd happily take it off your hands... In the meantime, is there another way to get communication from the Pylontechs? My thinking is hooking up a computer to them to read SoC, health etc. I get the feeling that I'm getting way less than the 7kWh capacity from the two and would like a way of checking that.