Solar Assistant integration of two batteries (two JK BMS)

Hi everyone,

I have a Growatt SPF5k inverter with two Lifepo4 batteries, each controlled by it's own BMS (JK 100A).
I there a way to connect both BMS's to Solar Assistant?

Currently it's only one connected via RS485 dongle and the details aren't accurate (-50%). Option would be to use inverter settings but I don't want to lose the details provided by the BMS.

thanks
Florin

Florin Radu said:

Hi everyone,

I have a Growatt SPF5k inverter with two Lifepo4 batteries, each controlled by it's own BMS (JK 100A).
I there a way to connect both BMS's to Solar Assistant?

Currently it's only one connected via RS485 dongle and the details aren't accurate (-50%). Option would be to use inverter settings but I don't want to lose the details provided by the BMS.

thanks
Florin

Click to expand...

Settings tab. Scroll down to battery. Click disconnect button. Choose multiple instances of your batteries. Easy.

You need this to physically connect BMS to Solar Assistant Raspberry Pi.

Above is link to JK RS485 to USB adapter. Don't know how to rename the link.

TomC4306 said:

Settings tab. Scroll down to battery. Click disconnect button. Choose multiple instances of your batteries. Easy.

Click to expand...

that easy? I have to RS485 adaptors but never came to my mind to connect a second one to the RPi.

I'll give it a try later today.

thanks!

It worked!

many thanks!

How is your battery connected to the inverter? Does it use the RS485 port?

Duckcm18 said:

How is your battery connected to the inverter? Does it use the RS485 port?

Click to expand...

Mine's not.
I want the chargers to be responsible for charging and the BMS responsible for bmsing.
Everything is monitored in solar assistant. The monitoring there is much more robust and complete then the monitoring in the inverter. Plus, I can't see the inverter data from everywhere.

Actually, they do communicate through the magic of physics.

About to pull my hair out and atomize the SA.
I’ve rebooted and still can’t see the two JKs. I can see one inverter and one JK but only two USB’s at a time. Using a power hub + the exact items as needed shown on the SA website. The only thing that works is the emulated bms. If doesn’t give me more port choices. It won’t let me have the screen shot in post #2 any ideas before it goes in the mulcher?

It might help if you resized the images. Too large to see on screen. Just click on them and drag a corner.

Do you have each device independently cabled to the pi?

I freaking found the problem. A bad one of these. I buy spares when they are cheap thank god. Thanks for the help guys and for listening to my rant.

A bit disappointed with what it shows. The Daly showed highest and lowest cell voltage. The JK’s state of charge is wrong. I connected them right after top balancing and if it’s basing it off of that it’ll always off. On the Daly I could set/correct the state of charge and never touch it again. I hope it learns SOC or do a back to factory reset.

Skypower said:

A bit disappointed with what it shows. The Daly showed highest and lowest cell voltage. The JK’s state of charge is wrong. I connected them right after top balancing and it’s basing it off of that it’ll always off. On the Daly I could set/correct the state of charge and never touch it again. I hope it learns SOC or do a back to factory reset.

Click to expand...

Good God.
Just let it cycle.
Everything will reset on your next full charge.
Solar assistant has nothing to do with that by the way. It only reports what it's being told by your inverter and your battery.

Skypower said:

A bit disappointed with what it shows. The Daly showed highest and lowest cell voltage. The JK’s state of charge is wrong.

Click to expand...

SOC indicator of BMSs are notoriously unreliable. Do not rely on it for any system management. If you want reliable SOC information you will need a good quality shunt.

I would use the BMS data to track voltages (high, low and cell differentials) and not a lot else.

I was considering a Victron shunt in the beginning then I found out that SA made changes to use JKs. Now I’m re thinking it. What’s new now is I’m getting a %per hour number under the battery state of charge that I didn’t see with Daly. Loose something, gain another. I wonder if I still get that with the Victron shunt. I’d seen that too with the emulated battery.

At present SA can only show you data from one type of battery source, so e.g. it will be either your smart shunt or the JK BMS data, but not both together.

Pierre does know this is an oft requested feature. As to whether/when it might be implemented, who knows.

For now because I can only choose one, I have chosen the shunt data over the BMS data. Mine is slightly complicated because I have a hybrid battery (LiFePO4 + lead acid) but in the end I want reliable SOC data as my system has automations which use this.

I am working on my own solution for getting both sets of data. Aside from waiting for SA to implement something that may never come, I have two options I can think of:

i. Implement the ESPHome - Victron Smartshunt project so that this data can be fed into my Home Assistant, and then let SA just read the BMS data.

ii. Load a second instance of SA on a spare RPi I have and use that to monitor one of the batteries and integrate within HA. Because I have two inverters, it would also be used for the other inverter (currently I have both connected to the same RPi). I don't know how the SA to Home Assistant integration will go with two separate systems. It should be fine but this is my second option.

At the moment I am working on i.

I have managed to navigate the process of installing the software on the ESP8622 board (that was the hard part for me as I am completely new to this) but am yet to do the wiring for the shunt.

When completed.
I will have the smart shunt and JK's connected.
I will run with the Smart Shunt at all times. And switch to the JK's if I need to look at something. And then switch back. Until when/if Pierre updates the function.

I was perplexed because I’d sworn I’d seen a screenshot where it reported high low and average cell voltage but when I looked back again it wasn’t a JK, it was actually a JBD screen shot. ? duh. Kinda nice to have seen that remotely, but oh well. W’ll wait a few cycles and see how repetitive the SOC is. I’ll adapt to say 50% actually means 65. If it’s too wonky I’ll just disconnect the Jk data and go with the Victron shunt. Thanks guys.

timselectric said:

When completed.
I will have the smart shunt and JK's connected.
I will run with the Smart Shunt at all times. And switch to the JK's if I need to look at something. And then switch back. Until when/if Pierre updates the function.

Click to expand...

Yeah, I can't really do that.

I mean I could manually select one or the other to have a look at the BMS data, but because the BMS data is for the LiFePO4 batteries only then the SOC will relate to those batteries only and not the entire hybrid battery.

My SOC value is used in automations, so even a brief peek can affect those. I guess I can set up a Home Assistant helper to disable those automations during a manual inspection.

That said I do want both sets of data as I like to track the cell voltage differential.

wattmatters said:

Yeah, I can't really do that.

I mean I could manually select one or the other to have a look at the BMS data, but because the BMS data is for the LiFePO4 batteries only then the SOC will relate to those batteries only and not the entire hybrid battery.

My SOC value is used in automations, so even a brief peek can affect those. I guess I can set up a Home Assistant helper to disable those automations during a manual inspection.

That said I do want both sets of data as I like to track the cell voltage differential.

Click to expand...

I think that your idea of two different SA sites is probably the easiest way to go.

How many jk bms can SA monitor?

Kornbread said:

How many jk bms can SA monitor?

Click to expand...

I'll let you know, next year. If nobody else does. lol