Seplos BMS

John mac

https://www.youtube.com/watch?v=0jAXjoC97dk&ab_channel=RayBuildsCoolStuff

think this shows it , shows all the connections anyway

championc

This a simple to follow schematic. This is for 16 or 32 cell setups, and follows the colour of the busbar wires from their connectors to the battery terminals. Hopefully this will be very useful for someone unfamiliar

irishchris

https://www.boards.ie/discussion/comment/118913195#Comment_118913195

Thanks as this will help a lot with my 16s2p setup when it arrives 👍

munsterfan2

Hi,

Top Balancing question, the bench supply readings are down to .05a at 3.65v (.2watts). Is this sufficient or should I let it site for a few more hours / days. (8 batterys is 100ah which is 20,000 x .05a so I am kind of thinking this is done).

Thanks,

reklamos

They are done. After disconnecting power leave them connected for a while.

fael

For those with the Seplos issues, could you give some details about your system? Or if you don't have issues, could you also give some details? Model of inverter, type of battery use (16s2p? or 2x16s1p?).

I have 32 cells on the way and looking to order 2x Seplos. I don't think there are any other good options out there, but would like to find out a bit more before pulling the trigger on the Seplos. Should I be looking at any other brands? Shame the Zeva isn't around anymore.

And perhaps this is a stupid question, but can you set the inverter to charge the battery to less than 100% Say 95% and avoid the overvoltage this way?

championc

I've 16 cells --> Seplos --> Sofar ME3000

Working like a dream

fael

https://www.boards.ie/discussion/comment/118953825#Comment_118953825

Cheers, I think it's only the Solis that is affected isn't it? I have a 6kW Solis Hybrid myself.

jfdelb

Hello everyone. I have a Solis RHI-6KW and I bought a SEPLOS BMS because theoretically it could communicate with the inverter, but from what I see it is not possible. Do you think it will be resolved or do I regret it? thanks

jfdelb

Hello everyone. I have a Solis RHI 6Kw and I bought a Seplos BMS because theoretically it could comunicate with the inversor, but from what I see is not possible. Do you it will be resolved or I regret it?. Thanks

reklamos

Solis does work with Seplos but there are some issues specifically when battery gets fully charged. This causes and error on Solis side and due to that error it diconnects the battery and PV. At least for me this state lasts 5mins or so after that Solis start working normally PV generates power and that is diverted or exported since the battery is full. Once there is not enough sunlight the battery start providing power and all errors are cleared.

It is annoying but it is not a show stopper(at least for me) the problem here is not Seplos but the way Seplos and Solis communicate.

My setup 2x16s1p and Solis RHI G4

John mac

so , BMS arrived today ...... 8S .. 😭

gona have to send it back .. unless anyone out there needs an 8S

irishchris

https://www.boards.ie/discussion/comment/118954858#Comment_118954858

So when the battery hits 100% the inverter just restarts production after the error then it will continue to work continuously just exporting or consuming usage?

It won't do it again and again on a continuous basis? If so could live with that but if it continually restarts throughout the good days then that is a big issue

reklamos

I would not say it restarts it just gets to that error state where it is not doing anything but for me it gets out of that state itself and starts working. I could see a case where it could get in this state multiple times during the day but that would mean that something would have to draw enough power to discharge the battery where all the errors are cleared and then you have enough sun for the battery to get charged to 100% again. Has not happend to me.

S'

I have a 32 cells arriving in May.

Whats the benefit in having a single BMS per 16 cell pack compared to a single Seplos connected to a 32 cells pack?

fael

https://www.boards.ie/discussion/comment/118955873#Comment_118955873

Could you get the battery to stop charging at say 98% and avoid the errors that way?

Fred7631

Hi, long time lurker, first time poster! I’ve got my battery, BMS and inverter all hooked up but I’ve messed around with the parameter settings thinking I could revert them when needed but don’t think I can? Has any one got the standard parameters they can export as XML? 16S lifepo4 pack.

Or even better, is their a standard set of settings/parameters that everyone is using for this setup? Are most going using between 20-90% state of charge? Are you letting the Solis control the battery or are you setting the Solis parameters outside the Seplos so it can take charge?

Also, can any one help with these settings on the Solis?

Cheers

championc

Here's my XML file of settings for my Seplos. Huge thanks to @garo for guidance.

I have pushed the top end values to try and bring up some cells which were lagging behind at the top end when charging.

Parameter 20220402_1210.txt

Fred7631

Awesome, thank you. Do you also have a Solis?

championc

No - a Sofar 3000TL PV Inverter a Sofar ME3000 Storage Inverter

Fred7631

Ok, so I'm struggling to get my (BMS) 100% charge sorted. I'm presuming I have this correct. The BMS should get to 100% and then go into standby. I can't seem to get this to work whatever I try. I've tried the default parameters, my own and the one you shared. At the moment I have 3.400v as the alarm and 3.300v as the recovery. The BMS detects that one cell hits 3.400 and drops the charge rate to 10amps but this then continues to charge the cells and they quickly all charge up to 3.65 and trigger the overvoltage protection. Something doesn't seem right here. Any ideas? Cheers.

jfdelb

I do not understand that SEPLOS does not solve this problem. They say in their advertising that SEPLOS is compatible with SOLIS and it is not true

garo

https://www.boards.ie/discussion/comment/118971370#Comment_118971370

This sounds like what should be happening. At the alarm level the BMR cuts current to 10A and then at protection level it cuts off current altogether. Note that once you hit 3.4 there is very little capacity left in the cells and then should reach 3.6 very quickly. The charge curve of LiFePO4 cells is not linear. Takes forever to get from 3.2 to 3.35 and then voltage rises really fast.

Fred7631

Thanks Garo, ok glad it sounds normal but if this happens then I get the BMS shutdown and ‘intermittent power supply waiting’ which doesn’t seem to clear and of course the Solis never does any charge or discharge from that point on unless I haven’t waited enough for it to clear?

reklamos

Mine recovers after 5 minutes. The error is still there while it is close to 100% but it does start discharge when needed. When BMS reaches 100% and errors are thrown the gneration stop and everything drops to 0 but it does recover. Here is graph from yesterday. You can see when it reached 100% and stopped generating but after 3 minutes it recovered and worked normaly

Fred7631

Thanks, I wasn't waiting long enough. You are right, it does discharge even with this error. I'm waiting to see if it charges from Solar with this error present. What do you have your Cell high voltage alarm and protection set to? Doesn't seem good to charge too high each day and high voltage protection will be hit every day/night for me so I'm thinking 3.450 alarm and 3.475 protection?

reklamos

By default it will not charge from solar untill it drops below 96%(check interval capacity setting) and this is normal, my pylons did the same. The voltage setting will depend on the cells and how well balanced they are. I have 3.4V for high voltage and 3.6V for overvoltage. For me it only reaches 100% on very good days. I only charge at nigh if battries are empty or if next days forcast is not good. I do not charge them fully overnight.

Fred7631

Thanks that now makes sense and works. Once I have this all sorted I want to try and make the charging smart by comparing to the forecast in HA? Has anyone tried this or got it working?

championc

https://www.boards.ie/discussion/comment/118973599#Comment_118973599

There are three things I see which could be to planned into this

1. Charge to xx% overnight if forecast sh1te.

2. Stop overnight discharge if forecast is < xx kW

3. Continue overnight discharge if forecast > xx kW

Fred7631

Yes, something like that would be good. Going to start researching now.

garo

https://www.boards.ie/discussion/comment/118972958#Comment_118972958

3.475 is probably too conservative for protection. I have mine set to 3.65. Yes to what reklamos says about 96%. It won't charge again until all the cells' voltage is below monomer overvoltage recovery AND capacity is less than 96%.

I can't be 100% certain but it did seem to me that my Growatt wasn't getting energy from the battery after more than 3 minutes at 100%.

Fred7631

Thanks. Still can't work out how the under-voltage alarm/protection is going to work correctly. Solis is only powered by 48V DC rather than AC.

When the BMS hits under-voltage / % alarm it drops the amps to around 2A which is (I presume) the amount the inverter is drawing.

This then continues to drop until under-voltage / % protection is triggered and after 1-minute this powers off the BMS which in turn powers off the Solis.

Which of course means the Solis isn't awake to send a charge during the night when it needs it. I imagine I'm missing something here. Does anyone have the same issue?

reklamos

https://www.boards.ie/discussion/comment/118989654#Comment_118989654

You should configure the SOC discharge on the inverter before it hits undervoltage or capacity protection on BMS. Once inverter reaches discharge SOC it stops pulling power from battery. You can see on BMS current goes to 0 and sits there till it starts charging again.

Fred7631

Funny you say that as trying that now but Solis discharge is set to 10% and 8% force charge and it's just gone through both of them without charging :( It did lower discharge limit to 2A @ 10.5%.

Also, the inverter will still be pulling power to stay on whether the BMS says 0.0. or not?

reklamos

https://www.boards.ie/discussion/comment/118989809#Comment_118989809

Some users had issues where FOC would not kick in. Instead of FOC I use backup mode with grid charge, this has not failed on me yet. Basically you set SOC(20%) above your backup(15%). The invert would stop discharge at 20% if power cut to occur it would use discharge from 20% to 15% before cutting. If the battery is not charged for long period of time(days) it will naturaly slowly discharge but since backup mode is configured once the battery reached 17-18% inverter charges it back to 20%.

If BMS is saying 0 current than it means 0. I have seen on some inverters where inveeter would say 0amps but Seplos would still be showing -0.6-1 amps but these were not Solis. In my case once the discharge SOC was reached I have not lost a single % overnight.

munsterfan2

Hi,

Still having issues with my setup, yesterday ran perfectly, with battery charging / discharging between about 80% and 40% but this morning when battery was at 40% and morning load came on initially draw was -11.52A @ 52.25v with cell voltages ranging from 3.174 to 3.238 but with cooker, microwave etc, draw increased to 58a and the cell voltages start to drop quickly, especially C9 which hit 2.9 giving a remaining capacity alarm with a total voltage of 48.3 and SOC dropped to 10% (20ah) which triggered the Seplos to do a charge.

With charge rate at 62a the voltage of the cells jumped again giving a total of 51.87, ranging from 3.269 but with Cell 9 very quickly jumping to 3.5 and triggering a "Monomer High Voltage Alarm". This drops charging to under 10a which results in C9 dropping to 3.427 within a few seconds and charging jumps again to 60a and within 10s it again jumps to 3.5 and this repeats.

Am I correct in thinking with a 200ah battery 60a is .3c so there should be no issue at this charge / discharge rate. Battery functions fine at the 20a / 30a charge/discharge rates.

Any suggestions, I have re-terminated the wires, polished the connectors & battery contacts with steel wool, moved the cell but issues move with it. Is it worth charging overnight at 20a, redoing the top balancing and resetting the Seplos ?

Thanks

reklamos

you could try to do top balancing again but it could be that you have a bad cell

SD_DRACULA

https://www.boards.ie/discussion/comment/118991956#Comment_118991956

Hmm if it moves with the cell maybe a bad cell?

What if you halve the amount of cells you have, leaving out the possibly bad cell too?

If it works ok then you know the cell is bad.

randombar

I'm currently in talks with Solis about updating my firmware, apparently it can't be done OTA.

I'm going to push to get it done anyway, does someone know of a battery that only works with the latest Solis Firmware? I've mentioned Seplos but they have come back saying they don't support that at any firmware.

munsterfan2

https://www.boards.ie/discussion/comment/118992126#Comment_118992126

AoBo if not listed in your current firmware will get you an update ( did for me )

Fred7631

Does using backup mode with grid charge allow you to set charge and discharge times?

graememk

Found this on thingiverse https://www.thingiverse.com/thing:5265259/files

Its a cover that clips over the main bit of the circuit board, Standoffs, and a screen case (and i think the screen case can mount directly on the clip on bit)

About a 10 hr print for everything.

graememk

First print went ok.ish, it's in PETG, only the screen case lid had first layer issues in one spot, maybe have to dial in the first layer settings a bit more.

Takes 9.5 hrs to print everything and I don't have any fittings to assemble it either ( I think it's m3), and some IPA to keep the bed clean.

Won't be able to do anything more on this for a few weeks though. But after that (and when I work out how much it costs me) If someone wants one tag me in the thread.

Fred7631

Has anyone come across an issue on the Solis where the Overdishg SOC: % gets stuck on an old value even though it shows as changed? I set mine to 15% a couple of days ago but now I can't get it to change. Discharging slows right down at 15.5% as if it was still set like that. Tried powering off AC+DC + complete shut down of BMS and multiple restarts and changing the discharge figures up and down and saving them but no joy. Any thing else I can try?

reklamos

https://www.boards.ie/discussion/comment/118994906#Comment_118994906

Yuo can still use scheduled charging with Backup mode.

garo

https://www.boards.ie/discussion/comment/118991956#Comment_118991956

Make sure your connections are tight. Worst case scenario is that you do have a bad cell. The same cell shouldn't hit UV and OV protection. That makes it unlikely to be a top balance issue and more likely to be either a poor connection or a bad cell.

munsterfan2

https://www.boards.ie/discussion/comment/119016651#Comment_119016651

Have some time tomorrow so going to move the cell, and check all the connections. Was reading on diysolar about graphing cell voltage vs current to see if any cells stand out. Will try that. What voltage difference is acceptable when discharging. BMS sit's at about 18mv when idle but as per image hits 60mv @ 14amp but I have seen it climb over 100mv at higher currents. with C8 always the lowest

reklamos

Was able to build an awful solution to pull seplos stats remotely to Grafana. It still requires a lot of work but it is start.

munsterfan2

Hi,

Looking at Reklamos very pretty graphs I went and plotted a few today. I seem to have a 2 batches of 8 cells that are responding together: The top group of 8 cells consists of Cells, 14, 15, 3, 9, 12, 04, 10 and 11, all within 5mv at the start of the graph. The lower group of 8 cells react much more sharply to higher current ( charge & discharge ) are 10mv away from the other cell group and have a range of 22mv from top to bottom, Cells 7, 6, 16, 5, 13, 8, 1, & 2.

Second chart is the cells and the discharge current (dotted line right hand axis) just as the SOC drops from 40% to 10%, which causes the inverter to charge back up to 15%

I think looking at this that I need to redo the top balance of the cells, especially the lower 8. If that doesnt fix then it looks like 8 of the cells have a different impedance and I need to talk to OYE. Does that make sense ?

garo

First check your connection between the top 8 and bottom 8. You need to screw the busbars on pretty tight. Also make sure your BMS sensors are above the busbar and not between the cell terminal and the busbar.

How are you guys pulling in the data from the Seplos? I am very interested in replicating your charts.