Solar Assistant with EVE LF280K 3.2V LiFePO4 280Ah

[jibberishballr]

I've been watching YouTube videos and searching through this forum, so if I missed something please direct me to a source of truth. I have Solar Assistant (SA) set with my 2X LV6548 inverters (Split Phase), 200a JK BMS- no additional communications to the inverter, and 16cells (EveLF280K LiFePO4 280Ah). I'm using the "emulated values" for reading in SA and running SBU as my output source priority.

Few Observations & Questions:

1. SOC and voltage are still a little confusing to me in the sense of which truly indicates battery life and when is the time to switch on the grid to support rather than running them too low. Solar assistant has Battery Settings which I have set based on some recommendations- still a little confused on what is optimal here, but my understanding is if you set the battery settings to lower than necessary you can utilize the "maintain battery state of charge" in the power tab rather than relying on these battery settings. Is this the right approach instead of using voltage? What would I change my battery settings to in order to best utilize the maintain SOC settings (see my current settings below)? I activated it last night (see screenshot 2) and noticed that this morning (6am) I was pulling from the grid until about 8am, then all good through the day with the battery being charged). It looks like SOC never went below 50% (see screenshot 3). Maybe someone could explain how I should use this setting in simpler terms?
   
   
   
2. What does each of these battery settings mean (screenshot 1)? Some seem self explanatory but I couldn't find the documentation that spells them out from SA.
3. I noticed that I can change one of my inverters (#1) to set "solar only" but when i switch to inverter #2 the option isn't editable and stuck on "solar first." Any ideas? I think it may be because the inverter is read from a parallel connection but not sure...
4. What are the min and max SOC I should see? Is it okay that I am 100% SOC during the day with battery kicking in after sun hours? What about how low SOC I should allow it to get down to? Want to ensure longevity of the batteries and utilize that "maintain battery state of charge" to the right %s (see screenshot 2).
5. Not as important but still curious as I set my kwH for the emulated values setting...I understand kWh = Ah × V/1,000. What voltage should I be using to make that calculation? If the cells are 3.2 and I have 16, then would it be (16x3.2)=51.2 meaning 280x51.2/1000=14.34 Kwh?

Hope this all makes sense and I can try and clarify and provide any additional details. Still learning this stuff.

Appreciate the help in advance!

 

[Adam De Lay]

SOC and voltage are still a little confusing to me in the sense of which truly indicates battery life and when is the time to switch on the grid to support rather than running them too low. Solar assistant has Battery Settings which I have set based on some recommendations- still a little confused on what is optimal here, but my understanding is if you set the battery settings to lower than necessary you can utilize the "maintain battery state of charge" in the power tab rather than relying on these battery settings. Is this the right approach instead of using voltage? What would I change my battery settings to in order to best utilize the maintain SOC settings (see my current settings below)? I activated it last night (see screenshot 2) and noticed that this morning (6am) I was pulling from the grid until about 8am, then all good through the day with the battery being charged). It looks like SOC never went below 50% (see screenshot 3). Maybe someone could explain how I should use this setting in simpler terms?

With LiFePO4 cells, voltage is very unreliable. You'll see charts out there which say a certain voltage relates to a certain percentage, but they're not reliable. The only time they get close is when your voltage gets really high or really low (but by then you know you're either near 100% or near 0%). SOC is whats used to reflect the power that flows in and out of your battery. It's really the most accurate option for LiFePO4.

So something to keep in mind is that your inverter can do this based on voltage (or by SOC if you have battery comms hooked up) and those settings in the inverter can conflict with the settings in SA, which is what I'm assuming happened in your case. The inverter is gonna switch to grid power when the voltage drops below 50v. If you want to use SA to control the grid switching, you'll need to lower your "To Grid battery voltage" down. I have mine set at 48v so that SA can switch to grid if my SOC reaches 30% (I also have my back to battery voltage at 56v to prevent the inverter from trying to switch back to the battery too soon).

On an additional note, I can't confirm how accurate the "emulated bms" is. I've always recommended getting a Victron Smart Shunt for the most accurate SOC tracking.

What does each of these battery settings mean (screenshot 1)? Some seem self explanatory but I couldn't find the documentation that spells them out from SA.

The battery settings correlate to the settings in your inverter. They might not be a 1-to-1 match with the wording, but it should be pretty close.
I'm going from memory here, but Battery Type I think is 05, Max charge current is 02, etc.

I noticed that I can change one of my inverters (#1) to set "solar only" but when i switch to inverter #2 the option isn't editable and stuck on "solar first." Any ideas? I think it may be because the inverter is read from a parallel connection but not sure...

There are some options that don't seem that you can change them when the information is coming across the parallel connection between the two inverters (i.e. you only have 1 inverter directly connected to SA). The other times I've see it takes a few seconds for the original change to be pushed to the inverter before you can make another change.

What are the min and max SOC I should see? Is it okay that I am 100% SOC during the day with battery kicking in after sun hours? What about how low SOC I should allow it to get down to? Want to ensure longevity of the batteries and utilize that "maintain battery state of charge" to the right %s (see screenshot 2).

This is one of those questions that you'll get a lot of different answers on. Same with "what voltage should I charge my batteries to". Lots of people have their own opinions and there really isn't a wrong answer. Some just go with manufacturer recommendations, others play around with what's best for their specific usage. Seeing 100% isn't bad, especially in the summertime. When you build a solar system, most people build around the winter season instead of the summer, knowing that they're gonna really over-produce during the summertime. There's days where I hit 100% just before noon, and other days I might barely make it by 1700.

As far as discharge depth, again, it depends on how you wana use the system. Some wana squeak out every last drop of power out of the batteries to maximize how much power they get, others only go down to 20% to increase the life of the batteries. As I stated before, I have SA set to change my system back to grid at 30%, but there's a method to my madness. I do that because I know that if I lost power overnight, 30% would be enough to supply power to loads to get me through till the sun came back up. If I didn't care about that, I would probably be discharging much lower.

Not as important but still curious as I set my kwH for the emulated values setting...I understand kWh = Ah × V/1,000. What voltage should I be using to make that calculation? If the cells are 3.2 and I have 16, then would it be (16x3.2)=51.2 meaning 280x51.2/1000=14.34 Kwh?

Correct. Typically you use the "nominal voltage" to do your calculations. Since your cells are 3.2v nominal, you would use that for whatever size battery bank you have.

Hope this helps.

 

[timselectric]

I've always recommended getting a Victron Smart Shunt for the most accurate SOC tracking.

This 100%

 

[jibberishballr]

Very helpful! Thanks @Adam De Lay

I checked the JK BMS app this am and it looks to be reading very similar to SA so I think that's a good sign. Last night through this am I hit 31% SOC and kicked to grid around 6am at that point.

Is it safe to assume that since I have it set to 30% on the Maintain Battery State of Charge Settings I can leave my voltage settings as is to continue only hitting ~30% SOC?

I have the Battery shutdown protection set to 20% so I'd assume I don't want to go much lower on the "To Grid battery voltage" or I'd turn off the inverters? Maybe I lower that to something much lower?

I'll dig back into the LV6548 settings to better understand the battery settings, just want to make sure I'm not adjusting anything in SA outside of a range that could be harmful.

I'll look into the Smart Shunt as well.

Once I add the other 16 cells, should be fully off grid usage which will be nice. Maybe i'll try to push them to a little lower SOC at that point but if there's more than enough supply, it probably won't get to that point. Since it sounds like there's no downside to having a full charge to help through the night, I think I'm in good shape.

Appreciate the info!

 

[Adam De Lay]

Not a problem!

Is it safe to assume that since I have it set to 30% on the Maintain Battery State of Charge Settings I can leave my voltage settings as is to continue only hitting ~30% SOC?

You can, just keep an eye on it. If you notice that your system's switching to grid outside of your SOC being at or below 30%, you'll wana make some adjustments. In the beginning I didn't pay attention to the fact that the inverter could switch to grid as well, so I was getting really frustrated when I was having my inverter constantly switching back and forth between grid and battery because the inverter and SA were basically "fighting".

I have the Battery shutdown protection set to 20% so I'd assume I don't want to go much lower on the "To Grid battery voltage" or I'd turn off the inverters? Maybe I lower that to something much lower?

If you set the "to grid voltage" really low, your inverter would almost ignore the setting, because your battery protection feature should kick in long before your voltage ever gets that low. You just want it set to a value that (as long as SA is running), your inverter should never fall to that voltage.

 

[jibberishballr]

Not a problem!


You can, just keep an eye on it. If you notice that your system's switching to grid outside of your SOC being at or below 30%, you'll wana make some adjustments. In the beginning I didn't pay attention to the fact that the inverter could switch to grid as well, so I was getting really frustrated when I was having my inverter constantly switching back and forth between grid and battery because the inverter and SA were basically "fighting".


If you set the "to grid voltage" really low, your inverter would almost ignore the setting, because your battery protection feature should kick in long before your voltage ever gets that low. You just want it set to a value that (as long as SA is running), your inverter should never fall to that voltage.

That makes sense. I had that happen the first night where I had the "maintain battery SOC" setting deactivated and there was constant switching of grid vs battery due to fluctuation of voltage. Very annoying haha. I'll try setting to that lower voltage (48) and keep an eye on it. I think I probably need to tie in an outlet to the inverter to have the orange pi and SA running off the inverter- otherwise someone (e.g. my kids) could unplug it....

I'll have to figure out how to get inverter #2 to go to "solar only" as I have inverter #1 set that way but #2 is set to "solar first." I'd like them to be uniform but I can't adjust those settings from SA for #2. Will keep tinkering.

Thanks again!

 

[Adam De Lay]

I'll have to figure out how to get inverter #2 to go to "solar only" as I have inverter #1 set that way but #2 is set to "solar first." I'd like them to be uniform but I can't adjust those settings from SA for #2. Will keep tinkering.

If you can't get it to change from SA, just go to inverter 2 and change menu option 16 to OSO. That will set it to Solar Only.

 

[jibberishballr]

If you can't get it to change from SA, just go to inverter 2 and change menu option 16 to OSO. That will set it to Solar Only.

Thanks, I tried but I think the Inverter and SA are duking it out over settings control.

Now, the SOC is not reading properly after having a fault yesterday and the BMS app was not liking the voltage levels so tweaking with that. SA was only seeing one inverter until I switched back to "user inverter values" and now the SOC is all over the place. Using voltage as a rough way to manage the batteries for now.
I was able to get back to emulated values but the "maintain SOC" setting doesn't help when the SOC is being read incorrectly. Restarted the inverters which caused some other issues (e.g. had to put them back into 2p1 and 2p2 along with some other settings like overload bypass being enabled). I think I'm going to do a fresh install of SA after I get the second 16 cells in and ensure the BMS settings are correct. Hopefully that works out the kinks.

 

[Adam De Lay]

Thanks, I tried but I think the Inverter and SA are duking it out over settings control.

Now, the SOC is not reading properly after having a fault yesterday and the BMS app was not liking the voltage levels so tweaking with that. SA was only seeing one inverter until I switched back to "user inverter values" and now the SOC is all over the place. Using voltage as a rough way to manage the batteries for now.
I was able to get back to emulated values but the "maintain SOC" setting doesn't help when the SOC is being read incorrectly. Restarted the inverters which caused some other issues (e.g. had to put them back into 2p1 and 2p2 along with some other settings like overload bypass being enabled). I think I'm going to do a fresh install of SA after I get the second 16 cells in and ensure the BMS settings are correct. Hopefully that works out the kinks.

I will say that when you make a change directly on the inverter, it does take a minute or so before it accurately reflects in SA. It’s not instantaneous.

In order for the SA “emulated BMS” values to be correct, I believe you have to fully charge your batteries so SA knows your at 100%, then it will track the amp hours flowing through. Still it’s not gonna be 100% accurate.

 

[jibberishballr]

I will say that when you make a change directly on the inverter, it does take a minute or so before it accurately reflects in SA. It’s not instantaneous.

In order for the SA “emulated BMS” values to be correct, I believe you have to fully charge your batteries so SA knows your at 100%, then it will track the amp hours flowing through. Still it’s not gonna be 100% accurate.

Just a quick update.

After getting everything reset, we have both BMS set up with both battery packs (560ah) and was able to get the inverters back in split phase seeing both inverters in SA. I still need to connect the BMS directly so we aren't using inverter or emulated values so that's next. Added a voltage reducer to keep the orange pi permanently connected to the batteries off the existing outlet. Disconnected my "grid" breaker and so far smooth sailing through the last couple of days with solely solar and batteries (I still have a couple outlets that are grid tied in case of emergencies where I can plug in garage freezers, fridges, etc.). Still learning how to tweak things but it's nice to have a functional and stable system.

Thanks for the support as I fumbled through this