powertrack
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- Joined
- Jan 28, 2021
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Do you know how to read the values? So what they mean? I guess the maximum voltage, SOC, maximum current is transferred here, probably encoded by IEEE754 Single precision 32-bit or 64 bitHave here a protocol from a BYD HVM 22,1kWh batterie, connected on a Fronius Symo Gen24 10kW
Goodwe is able to handle (after an firmware update) a BYD HVM.
Data read with BYD BeConnect Plus
would be very interesting to compare the data because in the setup of the old BYD B-Box HV (previous version of HVS or HVM) you need to set up your inverter brand. Not sure if this is relevant for the communication or just the interest of BYD.I've checked the data in the attached file, and it looks like a log file for debugging purposes. Real-time communication between the battery and the inverter can be quite different. The inverter datasheet states that it's MODBUS-based. If we have the actual log from the RS-485 bus, we can compare the data with the protocol between the Kostal inverter and the BYD battery.
auto can0 iface can0 inet manual
pre-up /sbin/ip link set can0 type can bitrate 125000
up /sbin/ifconfig can0 up
down /sbin/ifconfig can0 down
auto can1
iface can1 inet manual
pre-up /sbin/ip link set can1 type can bitrate 250000
up /sbin/ifconfig can1 up
down /sbin/ifconfig can1 down
Start service:
sudo systemctl start bmsd
Start service on boot:
sudo systemctl enable bmsd
Officially Goodwe doesn't support the usage of lead-acid batteries with the EH inverter series. But unofficially, I can confirm that GW6000-EH can work batteries without BMS with some limitations.
I'm attaching some screenshots from the "PV Master" app. When you choose a battery type, there is an option for a self-define model. Then it comes to a warning about usage of a lead-acid battery, and after that, you can choose battery parameters. The last screenshot shows the inverter using it in a self-define mode.
View attachment 23709 View attachment 23710View attachment 23712View attachment 23713
What are the limitations of self-define mode? The first issue: a SOC estimation doesn't match well for a Li-Ion battery and usually shows a higher value. Maybe LiFePO4 will work better. The second: max charging current is internally limited to 5.5A despite what you enter by the app.
There is SOC protection during discharge, but you can't set a min discharge voltage for the battery. Also, there is no temperature sensing in self-define mode.
I've been using my inverter in that mode for some time together with a Chevy Volt battery, but I think it's not suitable for Li-Ion batteries. I highly recommend BMS usage, and here is a screenshot of when there is a working BMS.
View attachment 23715
Hi @SeByDocKy and welcome to the forum.
A DIY HV LiFePO4 battery sounds interesting, but be aware of HV DC voltage. Now about your questions:
I also have plans to migrate to LiFePO4 at some moment in the future because of safety. I even started designing my own BMS solution and can share some thoughts if you are interested.
- Yes, I'm happy with GW6000-EH, and I think it works well at low light. I've seen as low as 20W PV power. It isn't easy to compare with other Chinese brands because I don't have previous experience. In my opinion, Goodwe has done a pretty good job.
- Good question, but I still haven't measured the self-consumption of the inverter.
- I think that a 5.5A charge current is a software limitation. But as I state before: I recommend a BMS communication with a default battery profile.
- I think it's possible. By "open BMS," you mean this project or something else? At 96V, you will be limited to 2400-2500W discharge power from the battery.
GreatI'm using the inverter in on-grid mode but without exporting energy to the grid. It's possible to set zero limits export value.
I hope tomorrow will have some more time and write more about the inverter and planed BMS.
OK, a few words about the inverter and its work. It has four main modes of operation:
View attachment 24254 View attachment 24255
I'm using it in general mode, with zero export to the grid. The generated PV energy is used for self-consumption, and I suspect this is not the optimal usage. I can't consume all energy produced by PV panels and usually end up with a fully charged battery on sunny days now.
An example of energy flow:
View attachment 24256
Usually, during the day, when the inverter charges the battery, there is a small consumption from the grid despite the energy produced by PV panels and house consumption.
An energy production on a sunny day (taken from Goodwe energy portal):
View attachment 24258
This is how the inverter typically works. I'm not sure how good it is compared to other brands, but I have no complaints, and the systems work well. I have some plans for an energy control and monitoring system using the inverter's MODBUS port, but thill will take some time.
@SeByDocKy, If you have some specific questions regarding the inverter, let me know. I understand the fact that these machines are quite new and there is little information available.
@SeByDocKy, a brief comments to your questions:
1) This consumption varies around 100-300W, which gives around 2-3kWh/day. During the nights, I noticed if increase load to the inverter (500 - 1000W), the grid consumption goes to almost zero. Bur during the days when charging the battery, there is a grid consumption. Here is an example form today with almost full power from PV array:
View attachment 24268
It's interesting that if I disconnect the battery, then the inverter reduces the grid consumption to zero.
There is some injection to the grid, but it's negligible, below one percent of the total produced amount.
2) It's a fanless inverter, and it's very quiet indeed.
3) This is an interesting project, and I will check it. Maybe I need such a device for the hot summer days. Some time ago, I found a similar device - Fronius Ohmpilot, but I think it works only with a Fronius inverter.
4. I've ordered my inverter from a German distributor. It costs me around 1400 euros, including shipping and VAT. I will send you the details on PM.