Help! BMS Growatt Communication, Split Phase.

[Zero_PD]

Dusty in the desert on starlink and -need some help. TLDR if anyone knows anything about BMS communication and solar inverters let me know.

We have four growatt inverters wired in split phase. They’re connected to a server rack battery bank of 9 batteries, 3 different brands. I have the growatt set to Li and CAN communication protocol.



When we fired everything up one of our four inverters started shrieking and its battery current protection fuse blew. 125a. We still don’t know what is wrong. However, our other two inverters are on another fuse. They appear unaffected. So we have just been troubleshooting with them each set to a different phase. The problem is now we cannot get any BMS communication to work. Typically we use can protocol and it just won’t work so our robots shut off in 30 seconds because it won’t see the battery. I don’t know a ton of the technical details of the communication, but we’ve never had a problem setting it a can and plugging in the ethernet cable and seeing at work. Something is wrong and I have tried switching between CAN and RS4845 and the ports on multiple batteries. And switching the comm mode on my master split phase inverter. It just won’t see the batteries. I’m stuck.



Something is wrong on multiple levels and I don’t know what. I am tempted to just go to a user to find battery charging mode, well that is definitely skipping over or ignoring an issue that we have not yet identified. I am wondering if my communication wires could be programmed or wired up incorrectly, but I’ve double checked them and they look fine. And I’m not sure how they might affect BMS.



Any ideas what might be going on? I’ve attached a few pics. Thanks.

 

[Kid Solar]

We have four growatt inverters wired in split phase. They’re connected to a server rack battery bank of 9 batteries, 3 different brands. I have the growatt set to Li and CAN communication protocol.

That's not going to work.

You'll need to ditch the comms.

Run open loop and set your voltages.

Would be a miracle if all four brands(I'm assuming you don't have a Growatt battery) you are using, use the same protocol.

 

[Zero_PD]

Hi thank you for the quick response. So ditch, the BMS and use user defined for my battery charging? Could you tell me a little bit more about how I should define the charging? I have checked that all of my batteries are within 100 mV of the same voltage. I charged them all manually with a DC power supply first. I typically charge them with my DC power supply at 5A or C divided by 20.

Edit; I found a thread about this. I will try user defined. I’m still really worried about why that fuse blew on my battery input. Was it something wrong with my split phase system? Does it look like there’s something wrong with the communication or current hearing cables?

 

[Kid Solar]

You'll need to charge them all to 100% individually.

The BMS is part of the battery. Don't do anything with them.

The voltage information should be available from your battery manufacturers manual.

 

[ChrisG]

That looks like a Growatt SPF 3000 inverter in the pic. You can get comms working using the YamBMS thread in this forum but it’s much easier just using voltage (USE mode).

 

[Zero_PD]

That looks like a Growatt SPF 3000 inverter in the pic. You can get comms working using the YamBMS thread in this forum but it’s much easier just using voltage (USE mode).

Thank you so much! Do you have recommendations for settings for USE mode?

 

[ChrisG]

Thank you so much! Do you have recommendations for settings for USE mode?

I’d refer to your battery manufacturer. Might need to average across all since you have different types.

 

[Kant_Hack_It]

What protocol are you set on?
What brand battery?
You'll have a hard time getting all the different brands of batteries talking, but if you have a brands that's a primary, it should work by setting the proper protocol

 

[Zero_PD]

I feel way outside of my expertise right now. I switched to user defined and things seemed fine. But our entire system is BUZZING. It steers to emit the most terrifying sound after 30 seconds. I have no idea what’s causing it. There are no errors on the inverters. Just a terrifying electrical buzzing sound, loud like a swarm of bees.

All connections seem good. I disconnected the battery bank and tried just one battery. Same buzzing. Does anyone know what I can try? I have NO idea. Thanks in advance.

 

[Kid Solar]

Well for starters these aren't outdoor inverters.

You have to set the voltages correctly on the inverters for your batteries.

Might be time to call in some paid help.