Seplos CAN BUS RS485 48v 200A 8S-16S BMS

[shavermcspud]

Couldn't agree more, I've been speaking with Seplos via the Alibaba chat function and they have been very helpful answering lots of detailed questions like "What type of connector is used to the balance cables".

Seems I spoke too soon, it has been or was working fine on discharge for about 5 hours at 40amps, then it suddenly has thrown new errors, now shows BMS under voltage errors, BMS overheat error @ 22 degrees C although its set at 40 degrees C, cell voltage failure on 1,2,4,8 & 13 at 0.100 volts even though they are at 3.35v respectively, ambient temp failure at 86 degrees C even though the rooms at 22 C, a low pressure overall failure, whatever that means. I give up.

 

[weirded]

Seems I spoke too soon, it has been or was working fine on discharge for about 5 hours at 40amps, then it suddenly has thrown new errors, now shows BMS under voltage errors, BMS overheat error @ 22 degrees C although its set at 40 degrees C, cell voltage failure on 1,2,4,8 & 13 at 0.100 volts even though they are at 3.35v respectively, ambient temp failure at 86 degrees C even though the rooms at 22 C, a low pressure overall failure, whatever that means. I give up.

Ah damn, that's unfortunate. Two failures in a row doesn't bode well.

 

[shavermcspud]

Ah damn, that's unfortunate. Two failures in a row doesn't bode well.

These errors are different to the first one, it showed cell voltage errors on 1&2 on the original one, this one has even more issues. Just reset it and now showing battery low voltage forbidden charging message even though its trying to discharge. I don't think the replacement they sent me is new to be honest, came in a tatty old box and all the terminals have seen plenty of use looking at the screw threads. Not sure I can ask for another replacement at this point.

 

[weirded]

These errors are different to the first one, it showed cell voltage errors on 1&2 on the original one, this one has even more issues. Just reset it and now showing battery low voltage forbidden charging message even though its trying to discharge. I don't think the replacement they sent me is new to be honest, came in a tatty old box and all the terminals have seen plenty of use looking at the screw threads. Not sure I can ask for another replacement at this point.

Maybe a refund is the thing to ask for. Too bad.

 

[houseofancients]

These errors are different to the first one, it showed cell voltage errors on 1&2 on the original one, this one has even more issues. Just reset it and now showing battery low voltage forbidden charging message even though its trying to discharge. I don't think the replacement they sent me is new to be honest, came in a tatty old box and all the terminals have seen plenty of use looking at the screw threads. Not sure I can ask for another replacement at this point.

well, as you have payed good money, why not ?
they seem to be a professional pack builder/intergrator so they should make it right

 

[Aaron Zhou]

Is there a protocol for the Deye available?

yes

 

[shavermcspud]

Does anyone have any pictures of theirs wired up and the settings you are using etc? Seplos are saying there is something wrong my end as this is my second unit which doesn't work under discharge

To confirm its not my cells or inverter, I tired all three of my old BMS's units on discharge for a few hours each and none of those show the same voltage issues on cells during discharge, left one old BMS on all night in discharge mode, was down to 45% battery SOC next morning so the cells are good,

I reinstalled the Seplos in the morning and all day it sat there in charge mode at 60amps charging the pack and tailing off current when the pack reached 55v without an issue, I wactehd each cell voltage rise throughout the day, it went in to balance mode at 3pm, balanced the pack by 6pm within 10mv, come low light with a mix of PV and battery it went in to discharge at 12amps for 2hours and it carried on working after sunset at 18amps for another 45 minutes then just shutdown showing cells 1,2,5,8 &13 as basically empty, these are slightly different to last times errors. checked the indicated cells with DVM and they were all around 3.38v

Ive checked and double checked the wiring to the BMS, the batteries and the inverter
replaced the canbus cable
replaced the DC cables from the inverter to the BMS with even bigger 400amp rated cables in-case of voltage drop
removed the inline fuse and isolator to test
I've pinned out each connector on the balance leads for continuity
I've checked in the software that there is no hard amperage limit set for discharge
I've checked in the software that the voltage cut off per cell is correct at 3.0v

logs from the BMS



It's odd that it will charge perfectly all day at 60amps but just wont discharge reliably for any usable length of time.
I'm either missing something silly or have been super unlucky with two faulty units.

open to suggestions.

 

[shavermcspud]

Update from support, they now say it might not be compatible with my inverter and or pylontech BMS can communication, even though my specific inverter is listed as compatible and others have successfully used the same BMS and inverter.

 

[houseofancients]

i have pointed seplos to this topic , when i discussed my order...

do you have a growatt inverter ?
i have seen discussions somewhere in regards to the gyl and also the pylontech batteries that actually required a firmware update for the inverter

 

[houseofancients]

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[shavermcspud]

i have pointed seplos to this topic , when i discussed my order...

do you have a growatt inverter ?
i have seen discussions somewhere in regards to the gyl and also the pylontech batteries that actually required a firmware update for the inverter

No I have a Sofar Me3000SP A/C coupled battery inverter, its specifically listed as supported. Support came back to me today and said it was because I was using the pylontech protocol which wont work correctly (despite others using the exact same hardware as me under pylontech) They told me to change it to sofar can communication which I have done, worked for an hour this time on discharge and failed again with shutdown showing other random cells being empty.

 

[houseofancients]

No I have a Sofar Me3000SP A/C coupled battery inverter, its specifically listed as supported. Support came back to me today and said it was because I was using the pylontech protocol which wont work correctly (despite others using the exact same hardware as me under pylontech) They told me to change it to sofar can communication which I have done, worked for an hour this time on discharge and failed again with shutdown showing other random cells being empty.

the protocol doesnt work for the inverter, or is it comming wrong out of the bms..
hate to say it, but i hope it is the first option, as my setup will relay heavily on the pylontech protocol ( voltronics inverters) .

i hope for your case it gets worked out soon and completely..

 

[mcdonder]

Has anyone tried this with success with an SMA Sunny Island?

 

[shavermcspud]

the protocol doesnt work for the inverter, or is it comming wrong out of the bms..
hate to say it, but i hope it is the first option, as my setup will relay heavily on the pylontech protocol ( voltronics inverters) .

i hope for your case it gets worked out soon and completely..

I'm not sure which one it is at this point,I don't think my inverter is at fault, i have upgraded the firmware on that yesterday evening and its still doing the same, the inverter logs show the BMS sent a shutdown command, as for why I don't know. Considering Seplos sell pre made rack batteries with this same BMS installed as pylontech replacements, by all accounts they have sold thousands of them so they must work.

 

[houseofancients]

I'm not sure which one it is at this point,I don't think my inverter is at fault, i have upgraded the firmware on that yesterday evening and its still doing the same, the inverter logs show the BMS sent a shutdown command, as for why I don't know. Considering Seplos sell pre made rack batteries with this same BMS installed as pylontech replacements, by all accounts they have sold thousands of them so they must work.

did you get it going ?

 

[shavermcspud]

did you get it going ?

Yes I did, feel a bit of a fool to be honest, it ended up being the supplied BMS cable that came with the inverter, I'd even bought a brand new one to try and made my own. Turns out pins 7&8 from the RJ45 end need to be cut and only 5&6 need to be connected, As soon as I did that it discharged fine. This might catch a few other people out potentially as the cable that comes with the inverter is for use with pylontech batteries and this BMS is stated as a pylontech alternative. The inverter manual shows 5,6,7,8 need to be connected but nothing in the BMS manual to state only pins 5&6. I would be interested to see if anyone else with the same kit as me had to cut the lines on their cable too.

 

[houseofancients]

Yes I did, feel a bit of a fool to be honest, it ended up being the supplied BMS cable that came with the inverter, I'd even bought a brand new one to try and made my own. Turns out pins 7&8 from the RJ45 end need to be cut and only 5&6 need to be connected, As soon as I did that it discharged fine. This might catch a few other people out potentially as the cable that comes with the inverter is for use with pylontech batteries and this BMS is stated as a pylontech alternative. The inverter manual shows 5,6,7,8 need to be connected but nothing in the BMS manual to state only pins 5&6. I would be interested to see if anyone else with the same kit as me had to cut the lines on their cable too.

good, glad to hear it does work.
was prepping myself today for the arrival of my bms later this week , so read the manuel.
i saw the same thing in the manual, so you're positive only 5&6 need to be connected ?
i'll start by making my own cable as to prevent the same issues...

after i confirm it works, i'll test it with the pylontech cable i have, but good catch !

how are you linking it now that it works?
especially like the precharge feature, althought wiring both positive and negative i've never seen in a bms before

 

[shavermcspud]

good, glad to hear it does work.
was prepping myself today for the arrival of my bms later this week , so read the manuel.
i saw the same thing in the manual, so you're positive only 5&6 need to be connected ?
i'll start by making my own cable as to prevent the same issues...

after i confirm it works, i'll test it with the pylontech cable i have, but good catch !

how are you linking it now that it works?
especially like the precharge feature, althought wiring both positive and negative i've never seen in a bms before

I would never have thought to remove the last two pins, I just put a new crimp on with 5&6 and its working exactly as described.
hundred percent sure only 5&6 are needed, thought maybe Seplos would have come across this before and made that their first mention in the support email but that was their last resort. It could be to do with certain revisions of the Sofar inverter that have this issue that they haven't seen, mines rev 1 of the new build with the external WiFi antenna. either way its working perfectly, cell voltage readouts are good and very accurate, balancing works a treat. I'm currently in the process of translating their BMS software to something that resembles English as its only and XML file. might be handy for a few people.

 

[houseofancients]

I would never have thought to remove the last two pins, I just put a new crimp on with 5&6 and its working exactly as described.
hundred percent sure only 5&6 are needed, thought maybe Seplos would have come across this before and made that their first mention in the support email but that was their last resort. It could be to do with certain revisions of the Sofar inverter that have this issue that they haven't seen, mines rev 1 of the new build with the external WiFi antenna. either way its working perfectly, cell voltage readouts are good and very accurate, balancing works a treat. I'm currently in the process of translating their BMS software to something that resembles English as its only and XML file. might be handy for a few people.

might do the same for a dutch/german version

great to hear you're liking it..
did you get the display too ?

 

[shavermcspud]

might do the same for a dutch/german version

great to hear you're liking it..
did you get the display too ?

yes, got the display, not sure how much use it will be, it goes dark after 30 seconds, cant seem to find a way to disable that, so no quick glance like my old BMS. when you reactive the display you have to scroll back through the menus to see the cell voltages etc