Communication between EG4 Wall Mount Batteries, and JK BMS

[hbattraw]

So after Will Prowse posted the video on the Yixiangpower DIY upright batteries, I bought and assembled one of them to add capacity to my 18kpv system with two EG4 Wall Mount batteries. It helps, but it doesn't communicate with the other batteries. The inverter only 'sees ' or communicates with the two EG4 batteries. That means the inverter will shutdown at night if the two communicating batteries reach zero, even if the yixiangpower battery still has plenty of juice left. Is it possible to get the batteries to connect and communicate? What are the settings? Do I have to update firmware on the EG4 batteries and/or JK BMS? Right now there's only three options for other battery communication protocols on the EG4 battery's. Eg4, Growatt (I assume GRW), and SCH (I don't know what that stands for). Is it possible to just have the inverter draw power from all batteries until each one hits 'zero' percent? I just wouldn't be able to check the status, and itf be relying on the internal BMS's to shutoff. Additionally, the batteries are different sizes. 280 for EG4 batteries, and 314 for the yixiangpower batteries.

The EG4 batteries were dead simple. Set the dip switches to battery one and two, connect the two batteries to the battery com ports via Ethernet cable, run the Ethernet cable to the CAN port to the inverter.

I found the off grid garage channel (or something like that) and just found out that some of the ports won't change their protocol on JK BMS 's. I'll have to review.

Thanks for any help!

 

[MaikaiLife]

I'm curious if you've made any progress on finding a solution to your question. @hbattraw ??

 

[hbattraw]

Yes and no. I've taken all my batteries off of closed loop communication with the 18kpv inverter (so they're all in open-loop state and each battery BMS is handling how much charge or discharge the battery is doing). The two EG4 WallMount batteries were originally in closed loop communication, with the inverter. This was really useful. I could see the exact percentage of charge , and everything else. But the inverter would shut down output if the two batteries died, even if there's was plenty in the Yixiangpower battery.

The solution was to change the battery settings on the 18kpv inverter from 'lithium' to 'lead acid' batteries. Then change the voltage settings using this video.

The image below is the the information you need for the float, absorption. I used the max voltage or the 'system charge volt limit' as 58.4V (16 cells x 3.65V). I put the charge and discharge limit as 280A. It should be able to change/discharge faster, because each battery should be able to charge at 200a each. It's limited by the two lines of 2/0 to the inverter (175A per line, or 350A together). I'm just being conservative.

I've literally only been running the system that way since yesterday. It seems to work fine. I can only see the voltage of the system though. If you want an estimate the percentage, then use the image below to estimate how much charge is left based on the battery voltage (which the inverter will tell you). For instance, my voltage right now is 52.6V, so I'd estimate my percentage left of about 55% based on the chart I attached.

I hope that makes sense. It's not quite as nice as having all batteries in closed-loop communication, but it works. The batteries stay pretty close to the same voltage, and I'm able to use the full charge of all the batteries. Cheers!