Seplos 200 BMS stuck

[Logic28]

A novel problem for me, today my seplos 200 based 48v 304A battery after reaching 100% SOC entered the single cell over voltage protection followed soon after by the single cell under voltage protection and the remaining capacity protection as from my image



The display jumped fro 100% SOC to 0% within seconds, I’m sort of new to this BMS and I cannot see any way to change/cancel any of these warnings nor I can find any way of resetting the SOC.

I thought I might have to reset to factory default but even then when I hold the reset button for 6 seconds, as per manual, all I get is the battery turning on and off within that space of seconds.

Any Idea how to fix the problem?

 

[Tulex]

I have that same setup, but unfortunately can't help. I will ask though, is this the first run? My hunch is a bad connection on a balance wire, but others will chime in.

 

[Quattrohead]

Give it a load and some time, it will reset when the cells hit the resume/whatever its called voltage

 

[Logic28]

Give it a load and some time, it will reset when the cells hit the resume/whatever its called voltage

That is what I thought but I don't think it will allow loads as the output shows no voltage even though it has 55.6 v at the batteries terminal so nothing can com out in order to discharge.
Anyway, how can it show 0%SOC and 55.6V at the same time is behind me? Beside I would really like to know what is the default reset procedure for the future.

 

[Lt.Dan]

What does the BMS report the cell voltages are?

Its saying you have both a high voltage cell, and a low voltage cell which is quite hard to do without doing it on purpose.

My bet is a bad connection or a damaged BMS balance/sense lead.

 

[Logic28]

What does the BMS report the cell voltages are?

Its saying you have both a high voltage cell, and a low voltage cell which is quite hard to do without doing it on purpose.

My bet is a bad connection or a damaged BMS balance/sense lead.

Yep, it shows a definite over voltage that accord to cell 16, as high as 4.7v but how would this happened I do not understand.

Yet minutes later voltages are showing correctly (I double checked each cell V and for resistance too) and only SOC low warning now.

No apparent problems with the balancing wiring either, at least not at my end unless the connector was faulty but then again it worked fine for weeks.
I connected it to the inverter in parallel with another battery hoping that it will resume at some point.

 

[Tulex]

Has this battery been in operation, or is this the result of first startup?

 

[Quattrohead]

You have a balance wire issue between cells 15 and 16 by the looks of things.

 

[Logic28]

You have a balance wire issue between cells 15 and 16 by the looks of things.

So it seemed but minutes later all voltages were back to normal reading and all cells resistance is 0.22/0.24mΩ

 

[Logic28]

Has this battery been in operation, or is this the result of first startup?

It's been fine for weeks now, in isolation or in parallel with a smaller one. Today it was working alone but I wanted to charge the other battery and which showed a similar voltage but when I connected them together the problem started. Never did it happen before

 

[Logic28]

It's been fine for weeks now, in isolation or in parallel with a smaller one. Today it was working alone but I wanted to charge the other battery and which showed a similar voltage but when I connected them together the problem started. Never did it happen before

 

[Logic28]

its a neat setup internally so I cannot immagine any wiring issues

 

[Logic28]

Solved (hopefully)
I left the lids open for a couple of hours so that the LED would stay on an discharge the cells not too aggressively and connected it in parallel with a smaller 100A and one of the two inverters (I was going to set them up in parallel tomorrow) hoping that as soon as the alarm was reset it would start giving some of its power to the smaller battery.
And so it happened since the 100A was at 37% before and jumped to 47% in about 40 minutes.
At the same time the Seplos 304A SOC resumed to 87%.
I still do not understand why and how this accoutred and I'm still waiting to see if someone knows hot to reset to factory default should one needed to do so.
Thanks for your inputs guys

 

[Quattrohead]

So someone has built that for you is that correct?
Regardless of that, now you say the fault is intermittent I am absolutely certain you have a bad connection there somewhere in the balance leads.

 

[Logic28]

So someone has built that for you is that correct?
Regardless of that, now you say the fault is intermittent I am absolutely certain you have a bad connection there somewhere in the balance leads.

Thanks for your input
BTW, nobody ever build anything for me . . . no electrical, no mechanical, no plumbing, no buildings, no musical equipment, no cinematographic equipment and that is because I only trust myself to do things that I have to use and if I don't know how, well then I do my homework first, a very intense and time-consuming homework however, there is always something new to learn and I guess that is why people like us, entertain themselves in new projects every time.
Should I make a mistake (rare and due to distraction) I use the difficulty to my advantage and learn something new.
I posted my last message so that my experience can be beneficial to others that, like me, indulge themselves into a new project with no previous experience and encounter similar problems.
This fault is not intermittent and there are no loose connection, all torqued adequately and coated with expensive conductive paste perhaps a fault in the BMS balancing/voltage detection area?
This only happened once since I built the battery two months ago (and the all PV system last year) however I shall keep an eye on it because I have seen others with minor problems in conjunction with Seplos BMSs.
In any case I see that nobody so far has come up with how to reset a Seplos 200E to factory default, perhaps I'm not the only novice around

 

[houseofancients]

Yep, it shows a definite over voltage that accord to cell 16, as high as 4.7v but how would this happened I do not understand.
View attachment 203800View attachment 203802
Yet minutes later voltages are showing correctly (I double checked each cell V and for resistance too) and only SOC low warning now.
View attachment 203822View attachment 203824
No apparent problems with the balancing wiring either, at least not at my end unless the connector was faulty but then again it worked fine for weeks.
I connected it to the inverter in parallel with another battery hoping that it will resume at some point.
View attachment 203829

I can almost guarantee you that :
1. Busbars aren't torques to 4-5 nm
2. Because of that heat that was created causing an even worse connection for sense wires.
3. Conducting paste is bad

4 possibly the connector in pcb to and from BMS aren't seated right/pushed all the way in

 

[RV8R]

Thanks for your input
BTW, nobody ever build anything for me . . . no electrical, no mechanical, no plumbing, no buildings, no musical equipment, no cinematographic equipment and that is because I only trust myself to do things that I have to use and if I don't know how, well then I do my homework first, a very intense and time-consuming homework however, there is always something new to learn and I guess that is why people like us, entertain themselves in new projects every time.
Should I make a mistake (rare and due to distraction) I use the difficulty to my advantage and learn something new.
I posted my last message so that my experience can be beneficial to others that, like me, indulge themselves into a new project with no previous experience and encounter similar problems.
This fault is not intermittent and there are no loose connection, all torqued adequately and coated with expensive conductive paste perhaps a fault in the BMS balancing/voltage detection area?
This only happened once since I built the battery two months ago (and the all PV system last year) however I shall keep an eye on it because I have seen others with minor problems in conjunction with Seplos BMSs.
In any case I see that nobody so far has come up with how to reset a Seplos 200E to factory default, perhaps I'm not the only novice around

Glad you were able to solve it .

This; BTW, nobody ever build anything for me

IMO ,,, No Man is an Island. You have had plentiful “built for you”.

I do lots of DIY projects, but I buy copper wire ,,, I do not have a copper mine & don’t scratch it outta the ground with my bare hands. Every time I pull out my wallet, someone has “built” something for me.

We have different perspectives I guess .

 

[Quattrohead]

No offense meant but it sounded like it was built by someone else.
Make sure your LED's are powered from all 16 cells....I once powered a 12v fan from 2 cells to keep the speed down and it slightly messed up those cells when the battery got low one time...the BMS could not control that load.
BUT, you still have a connection issue somewhere in that cell 15-16 area.

 

[Logic28]

Glad you were able to solve it .

This; BTW, nobody ever build anything for me

IMO ,,, No Man is an Island. You have had plentiful “built for you”.

I do lots of DIY projects, but I buy copper wire ,,, I do not have a copper mine & don’t scratch it outta the ground with my bare hands. Every time I pull out my wallet, someone has “built” something for me.

We have different perspectives I guess .

I had a feeling someone was going to say that and that is correct, but you you read I said "no one ever touches my projects" obviously I have to purchase the raw materials but all the machinery and manufacturing whether that is lathe, milling, tigging, coachwork, competition engines and no reason to mention the rest considering I'm 71 this year . . . . . All that has always been done by me and only me for the very reason I expressed before but I say this very carefully and humbly, I do not and I repeat do not trust anyone to deal with my projects and to prove that, when in a couple of occasions I allowed close friends to do some of my work, it has only been a costly disaster.
It's a sort of "protection mode" for me LOL

 

[Logic28]

No offense meant but it sounded like it was built by someone else.
Make sure your LED's are powered from all 16 cells....I once powered a 12v fan from 2 cells to keep the speed down and it slightly messed up those cells when the battery got low one time...the BMS could not control that load.
BUT, you still have a connection issue somewhere in that cell 15-16 area.

No offence taken it's just a touchy subject for me as I've olny had horrifying experience when I was forced or I allowed others to take over even just a small part of my projects.
Absolutely, the LED's ar directly connected to the Battery terminals and adequately fused with their proper loom with connectors, dedicated custom made circuit boards and further protected by acrylic custom covers

same as what I've prepared for the Balancing module's harness to be fitted soon, even though it seems not such an urgency.